there are many matrices that compare features.
i do believe that these two products are pretty much comparable regarding to features, but you can check it here:
warning: the feature matrix may not be 100% up to date, but it's sure very close.
i also believe that any significant feature found on one but not on the other (and many that exist on neither) can further be implemented with the use of MODs.
unfortunately, to this day i was not able to find any serious comparison that relates to performance. fwiw, i believe that these two packages lag pretty far behind phorum
as far as performance is concerned, altthough i can not back it up by evidence.
if you'll find any good comparative data wrt performance, i will be grateful if you could post it here, or better yet, post a link to the actual source.