i only tried it when it was at early stage where it kept crashing and caused some problems with windows.
I suggest watching sales for toon boom software but if you want one for free, krita is working on a interesting animation feature . Still, i wouldnt say spriter is bad, it enables you some badass techniques that can be used directly in c2 and its not just character animation, You could animate traps with it that otherwise would be really difficult to make with just events. Just saying. Then there is that Spine, that seems to be based of spriter but appearently has more features developed for animation... oh yeah, there is also that live2d, that has sometimes crazy sale offers but has interesting features