I was on DeviantArt back in the day when it was the art community, basically facebook for artists, and I had a following there when I started my comic, so I started uploading my comic there as well at the time. I was never big on the forums or anything on DA so I can't speak to that.
I haven't had any bad experiences, personally, but I have noticed a huge dropoff in terms of interaction. A few years ago, getting 0 comments on something meant it must be a thing that seriously nobody could relate to -- now, getting 0 comments on a piece of art isn't surprising. I tended to get more interaction before, whereas now, my art just gets a little burst of favs and occasionally a couple of comments, and my comic pages generally get one or two comments and 4-6 favs per page.
There are still new people following me though. Like every week or every other week there's another couple of people who discover and follow me. So it's weird, it feels like, there's probably still people here, it's not dead... but it's definitely not like it was back when it was a bustling hub. It feels very quiet.