I was just talking to my boi about my experience with composition in Audition.
I basically told him, if someone said I had to produce a track in it I would at least go down kicking and screaming against it before I did.
If you wanna try go ahead, but I personally hate it. But I LOVE podium. It gives me a feel of Reason, but with VSTs.
To answer your question tho, I love Shortcircuit (1, not 2). Nothing comes close. UVIworkstation is a wonder, especially with the pitch shift and timestretch.
For drums I been using Shortcircuit 2, but I recently found Tatapoum, which I must say I am favoring due to it closeness to ReDrum (yes, I'm a very advent Reason user and Propellerhead fan), so its a sampler, sequencer and both simul (which makes an excellent live performance instrument). Grizzly is also great, but I wouldn't have searched for more if I were satisfied with it.
DSK makes terrific instruments, mostly synths.
LoopDrive, great loop sampler.
Effects, Classic Pack, GVST suite (i guess you can call it), ReaPlugins (from Reaper) I use these always (along with a few others).
Peep out KVRAudio, mainly where I search for VSTs. (might be where most of us here search)
