I currently have a surface pro (2017) and before that I used a surface 3. Before that I had a Wacom bamboo tablet, but like... A really old one.
I've got kinda complicated feelings.
a lot of surface reviews are kinda hype-ey. Yes they are well built machines and the pen works well - but their form factor is also really fucking awkward. After awhile you kinda get used to it - but I always feel like I'm making compromises with a stubborn friend rather than learning how to make the most of the machine. In the ~5 years of using a surface, I've never gotten better at it, just used to dealing with it's issues.
Now of course - an off screen tablet is also awkward, but mostly because you have to develop some hand-eye coordination skills. I never felt like I was restrained by the form factor of my old bamboo like I do with my surface.
A lot of tablets claim to offer a "natural drawing experience" but in my experience this is never the case. Drawing on a computer, even using an on screen tablet, will never feel as comfortable or as natural as drawing on paper for me. That said, digital art makes up for this by giving you a lot of options to polish up your work. Every medium has its strengths and quirks, be it digital or watercolor or oils or crayons.
I think the next digital drawing tool I buy is either going to be an off-screen tablet, or a large on-screen tablet like a cintiq. That's not to say I've been disappointed by my surfaces - they've been really nice and they're easy to carry around, which has been useful as a full time college student (not that I really use them on the go, but rather from desk to desk.) But after I graduate I don't feel like I'll need to be as mobile as I am today, and as I get older I want to take care of my back better (on screen tablets kinda encourage you to sit in really uncomfortable positions in a way that off screen tablets don't).
Anyways - hope that helps!