SAI is really good an comfortable, but it does have many limitations. If you think you may need photoshop in the future just get that instead. At first was a struggle, and i missed SAI a bunch but now that I am learning it I'm not switching back. It won't cost you more than a mc donalds lunch once a month. It's totally wor4h it
Sai is great as a lightweight, easy-to-use drawing program. It lacks a few essential tools that Photoshop has (text-tools, for example), but it is otherwise really good - it's definitely easy to learn how to use. I used it a lot, and I still love sketching in it, even though I've otherwise switched over to Manga Studio/Clip Studio Paint.
If you're looking for a more serious tool to make comics specifically, I heartily recommend Manga Studio/Clip Studio Paint - it is amazing. And I think the sale Uzuki mentioned is still on. It is WELL worth the money, and will be able to do pretty much everything Photoshop can do. The only thing it lacks is a native CMYK-format, but unless you plan to print your comics, that won't be much of an issue.
When Sai 2 releases whenever that will be it will have a text tool and perspective guides and much more. Here is the official site http://systemax.jp/en/sai/5 Also, the only problem I have with clip studio paint is it isn't very good on low spec computers it requires twice as much ram to run and can't be run on more than one pc
I love Sai. It draws great and has smooth brush strokes. But t has some flaws like a small amount of blending modes, and no possibility of putting text in your drawings. But luckily it correspondents with programs like Photoshop.
It's currently in beta, and the latest version can actually save... but only as bmp and .sai2 (similar format to .sai, can only be used in sai2) ...I guess you COULD just save as bmp and then save it as something else in another program, but that sounds like a hassle... If you already have a SAI license you can use the same one for this. The text tool, from what I've tried, isn't the best but at least it HAS text now.
It's still in development, it just goes... veeeeery slowly. I think it took over a year between the current beta release and the previous one?
I use sai all the time and I love it but I mostly use it to make fun paintings and such I actually draw most of my comics by hand because proportions are hard for me to do with a tablet. /=
It's got a realyl nice painterly feel if you like to color things and I think the water color tool is amazing. I say it's totes worth trying
I use sai for my entire comic making process, and I'll say straight up that if you think it's limited it's because you never learned how to actually draw. The program has amazing brushes, all the tools you could possibly need (except a text tool I'll give you that), and you can create anything from super simple cartoons to hyper realism with it if you just, well, know how to actually draw.
It does have an equivalent of a burn and dodge layer (shade and luminosity) (also I was pretty sure burn and dodge had been confirmed for bad tools because they just don't look good but I guess whatever floats your boat), if you can learn how to draw a simple circle dialogue bubbles aren't a problem, and getting good blending really isn't hard as you can adjust the setting to make any of the brushes a blending tool. (You can even create and add your own brushes if you look up a simple tutorial) It creates some of the smoothest lineart there is, too, so I'm honestly not sure what you guys are going on about with it not being good for lines. Heck it even has one of the best stabilizers I've ever seen.
I will also say that you should buy the legal version. It really is not expensive, and it's a great program that deserves support.
Uh, no, I know how to draw, and I think SAI is limited because a.) it lacks a text tool and certain shape tools (there is no circle tool, and unless you are da Vinci and you can draw a perfect circle freehanded, then a circle tool is a nice thing to have), b.) it lacks many of the layer and blending modes available in, say, Manga Studio/Clip Studio Paint and c.) There are no perspective rulers, which are immensely helpful, and while I know it's perfectly possible to draw good perspectives without those tools, they are extremely useful tools if you can get them, and d.) its magic wand tool is not the greatest.
A better, larger program won't teach you how to draw, that's true - but SAI is lightweight, especially if you're going to draw comics. And I say this as someone who has completed professional illustration jobs using only SAI, because that's what was available to me at the time.
I will give you that it does amazing lines, especially compared to Photoshop - but compare it to Manga Studio/Clip Studio, and it comes up kind of short.
Since everyone has already posted about how awesome SAI is, all I can is - SAI is love, SAI is life.
I straight up admitted that the lack of a text tool was its one real shortcoming, and I agree that at least is a problem, but the rest of this is goofy, haha.
a.) Shape tools are something that really shouldn't even be used in the first place due to the generally artificial and out of place look they give, but there are multiple methods to drawing a perfect circle or a square in sai that honestly aren't difficult at all. Specifically the method of simply dropping a dot and erasing the inside, and using the curve tool both work well. Heck, I even found a third way looking for links to these examples, haha.
b.) After looking up the layer options in Manga Studio and Clip Studio Paint I'll straight up say they're unnecessarily complex, and you can get the same exact effects in Sai just using different methods and tools. Sure they might be nice if you're feeling lazy, but they aren't by any means offering you anything you couldn't achieve just using sai.
c.) Perspective lines take all of about two seconds to sketch out. Sai has a means of making lines with literally ever brush it has, and once you get right down to it all perspective is is a dot or two or three with a bunch of lines coming out of it. :/
d.) The magic wand tool is so adjustable you really can get it to do just about anything you want. You just have to take two seconds to actually look at the settings and adjust them to whatever it is you're doing.
Like, I'm not trying to start an argument or anything, I guess my point is that sai, while simple, works perfectly well for drawing and comic making. The additional tools found in other programs are just a lazy way of doing the exact same thing you can do in Sai, and, again, if you understand how to draw in the first place you probably won't need most of those tools. It's always astounding to me how many people act like a program not doing everything for them means it's somehow lacking in something, lmao.
Its not just being able to do it, its also about efficiency. Perspective lines don't take two seconds, maybe if you're draw 2 objects or don't draw backgrounds. Oh and by the way this statement you wrote sounds like an argument. Its sounds kind of degrading. Sai's purpose is to be light weight and limited and easy on the user. "this software make digital art more enjoyable and comfortable" is a quote directly from their website. While Clip Studio Paint/Manga Studio's purpose is to make creating comics efficient and fast without costing as much. Just check out their front page. Even pros have trouble with perspective and difficult angles. http://www.clipstudio.net/en1.
Like @AnnaLandin said
And by your logic the lack of a text tool isn't a real short coming because their are multiple methods to add text in sai that aren't difficult at all. All you need is a free word processor and print screen. You're comment sounds a little to high and mighty.
I was going to say the same thing, it's not about laziness, it's about efficiency. And the more efficient the program you use is, the more comics you'll have time to make. If anything, we're all lazy for using any kind of digital drawing tool, compared to those who draw traditionally, right? 
I know how to draw in perspective, but it's really time-consuming, and so I get bored, and so I often choose to draw things in a way that I won't have to worry too much about perspective. I use Photoshop now, and that will always be my preferred drawing tool, but I am seriously considering buying Clip Studio Paint or Manga Studio just for the sake of getting more help with the perspective drawing - it would save me SO MUCH TIME.
