I would say for me...
1) better room sounds. the room sound is probably the number one thing a drum modeling program needs to do well in order to get great sounds. Much of the drum sound for rock and older genres comes from the ability to to use the OH and rooms as the foundation of the sound. The OH and Room sounds currently just tend to not sound up to professional quality and there's a lot of difficulty getting them to sit in a mix, unless I'm working on something heavily stylized. In general the modeling of modo within a real space gives the drums a tinny somewhat hollow quality that I find difficult to mix with. I usually have to send all the drums to some sort of other plugin like Tverb, UA Sound City, or Cinematic rooms within my DAW to get a more workable room sound. But still whatever the room simulation within the OH and individual drums themselves is still a bit strange. Slightly tinny, and it has a way of making the transients not as sharp or impactful. Even with a custom room sound in the DAW it's hard to get rid of that tinny quality. The mixes that sound the best tend to best so far with modo tend to be ones where the style calls for dry with very little room or OH sound. Similar to what Dance Tech does here...
https://www.youtube.com/watch?v=yiLuDyvSjho. Also the ability to add pre-delay to the room sound would be ideal.
2) More accurate OH modeling sounds. I have noticed that many of the OH sounds for the drums add in a lot of extra boxyness and cardboardyness to the kick and snare (even with EQ trying to take it out) that wouldn't necessarily really be there in a real recording. An example is this video, you can hear that the OH mics don't have an extreme boxyness to them.
https://www.youtube.com/watch?v=q2ccgv4jaiE. In modo, the OH almost never has a bass to it, when real OH recordings can... and It can be very strange sometimes with Modo where the kick itself won't be boxy, the room sound won't be boxy, but the overhead will be extremely boxy and carboardy and it sounds like it's a completely different kick. The snare at times can have this quality as well. It makes it limiting if you try to go for a lot of rock or older sounds where the OH was very prominent.
3) more tight dampened kick sounds. Currently it's difficult to get a sound like say Michael Jackson's Billie Jean, TLC's Waterfalls,
https://www.youtube.com/watch?v=8WEtxJ4-sh4 and therefore many funk or hip hop type sounds. In these the kick is heavily dampened and tight and low. This would really open up Modo to be used more in hip hop and electronic music more easily. I feel like this is one of the most underserved sounds in all of the drum libraries out there and could open up a lot of potential. Especially since traditionally you can usually only find high quality versions of these sounds via samples or sampling the original songs they came from, and there isn't a lot of room for customization. But even more ability to do this for rock sounds would open it up a bit more. Think, AC / DC's Highway to Hell.
4) more ability to get "tea towel" dampening on snares and other drums. With the current dampening settings in modo, it still doesn't really give you this effect and this is an extremely common and sought after sound.
5) ability to change the actual pitch of the drums. The tuning capability does currently seem to mimic the actual tuning of head, which may not necessarily change the overall pitch that much. Ability to change the pitch up or down specifically would make it sit in mixes much better, as you would be able to tune the kick to the key of the song.
6) Ability to have mic placement in a room similar to Pianoteq. Another big aspect to getting a great sound is the ability to customize the mic positioning to a song. Examples can be found on this playlist from reverb where they try to recreate specific song and album sounds, where the specific positioning of the OH or room mics is quintessential to getting the sound.
https://www.youtube.com/watch?v=6lJ-l7F ... V&index=13