I recently started using Audition to edit sound for short film.
coming from Steinberg's Nuendo there are several features that i make me prefer audition over nuendo - especially things like the non-destructive clip-based use of effects and filters.
however there are some things that make audition close to unusable for editing of films that are longer than a few minutes (for me at least):
my main problem is that there is no way to organize the tracks in the multitrack editor into collapsable folders - as soon as you start getting in the ballpark of 30 audiotracks plus maybe 10 bus tracks the multitrack view is becoming very hard and tiresome to navigate.
and for longer films (not even feature length, maybe 10-20 minutes) i sometimes end up with almost 100 audio tracks (in Nuendo) -- right now for me it is impossible to work with track numbers like this in audition.
to be usable with high track counts, collapsable folder tracks (eg. seperate folders for dialog, foley, fx, atmo, ... tracks) would be good way to keep large projects clean and easy to navigate
folder tracks could also be used in the mixer window - preferably with an option to either *show all tracks* or *follow folder mode* (tracks in collapsed folders do not show up in the mixer)