Ok let me clear something up. The reason I rely on external libraries is so they can do the work I don't wanna have to worry about. But of course the problem with them is that they complicate the deployment process, since everyone has to be able to download and compile and set up the libraries separately, both users and developers. I never really went into this for the performance or whatever.
Anyways, nobody had an issue with SDL or SDL_mixer, but overtime people complained that SDL_gfx had some bugs and could be hard to compile (dated Mac project, etc). So I reported the problems to the SDL_gfx author and went looking for other promising alternatives, and SPriG was what I found. So I wanted to know if people had the same issues they had with SDL_gfx, if it was easier to download / compile / deploy on their various platforms and systems and such. That was my main concern, I'd be replacing one dependency (SDL_gfx) for another (SPriG) so I wanted to know if that was for the better. Because for me it's a non-issue, but I don't know about everybody else, that's what I want feedback on.
Stuff like activity, performance, etc, it's all highly subjective. A library can be as ancient as 1990 but still work fine out of the box, likewise a really active library might just mean it's constantly full of stuff that needs bugs. Performance can vary wildly from platform to platform and anything above 100fps isn't really noticeable. It can be a plus but it's not really what I'm looking for, plus both library authors have been pretty responsive to my feedback regarding bugs and improvements (otherwise we'd still have a broken globe and resizing and so on). On that note, if you have an issue with a library, feel free to tell the authors about it directly, it's the only way they'll learn.
In the end it's gonna be me programming and working with the library all the time so the choice will be mine, but you're not really helping me pick.