Thanks for the list, we're still having trouble deciding which one though...
Yeah, my team is still doing well on Dropbox so I can't sway you one way or the other. I will say that we tried using straight Github (which is what apps like Kactus essentially do) and it was a nightmare. Having designers run git commands is scary.
We ended up settling for Abstract despite the rough pricing plan. But it seems to run very nicely so far, and designer needs a UI to be honest :D
FYI, on large monitors the alignment between rows and headers is way off, making it very hard to read. Even more so in Firefox, where the table cells don't have borders.
Ah, Firefox strikes again. It appears that Firefox calculates width differently than other browsers. Working on it! Thanks for letting me know.