For me a virtual drum app replaces a real drummer … They just don’t quit the band all the time! 
Up until now I have used old style drum machines , Groove agent, EZ Drummer and Superior Drummer. They all have elements that I like… The sounds of Superior Drummer are great, the scope of patterns in EZ is awesome, GA was fast to get things going … And yes, the simplicity of 16 th note buttons on a drum machine was awesome to punch in unusual rhythms and percussion… I love lucky accidents.
BUT
Programming superior drummer a sound at a time is a nightmare ( for me). IN EZ Drummer finding the ‘right’ pattern combination takes enough time to kill the urge to do it. Automating GA to get variations was too fiddly, and no one can make a drum machine do a fill!!
So I’d like GA 4 to be able to get a beat up and running quickly. So I’d like to be able to create a single ‘GA track’ which drives the instrument for the entire song. Assign it a kit and a beat to start. Then as the song progresses split the track into sections which can be Intro, verse, bridge, chorus fill kind of designations. Roles really. Then be able to make fast and easy variations to each section until they fit the music being made. ‘Easy’ meaning a click or two. I saw an EQ plug in that worked by applying a preset then asking if the engineer liked the result. The user clicked YES or NO and refinements were made, hopefully intelligently, based on the response. At a certain point the engineer could drop into the real controls to take over. Kind of a cool way to home in on a result… Could beat making work in a similar way especially since most users aren’t actually drummers and might have a hard time ‘finding’ the right thing?
Within the sections of the GA track I envisage an drum instrument track/time based note editor break down of each sound which might have variable and independent styles, time bases ( half time, double time , shuffle , triplet , ) , accent controls ( flam, etc), sample editing for each sound in the part along with mixing controls.
The notes on the individual tracks would of course be individual hits and could be moved as any other musical note in CB. But perhaps logical units within the playing ( a fill, a flam, etc ) might appear as a single event for easier relocation and copying. This would also allow the user to click on it to get a variation, in the instance only that bit was inappropriate. Of course I’m sure these units could be expanded to reveal the actual hits within.
There should also be an actual drum set UI with an automatable drum mixer with local ambience, EQ , compression ( VST plug in based) . Perhaps this mixer might also mirror itself in the main CB 7 Mixer too… For those who like to line up the whole project at mix time.
I agree that having a Beat Designer kind of sub grid-editor that could be used as a loop within the over all GA Track would be great. Maybe a ‘sub instrument’ that could be placed at strategic points for little percussion bits or flourishes.
I guess I’m arguing for GA 4 to be tightly integrated into CB. For it to act like drummer… play along basically with a new song, then let me ‘teach it’ refinements quickly and easily as the arrangement develops… Yet like a real player still leave us room to take advantage of the happy accident!
Hope this makes vague sense… but you did ask! LOL
Lee