I have to admit, OZ has been my favorite ROM since my 5500 days. But off late I'm using Proto's excellent tkc ROM and I'm very satisfied.
I always felt OZ is almost there...if a few more apps could be fixed, I'd switch.
So here goes my list!
Ability to use NetFront on OZ or a stable konquerer with NetFront like features
A good mail client like the one on sharp rom
All Hancom apps should work
A decent Media player (audio/video)
Auto rotation on C7xx series
Of course I'm sure most of the apps in the above list is probably working on OZ but a dedicated feed for OZ compatible apps in the lines of Proto's Rom would help a lot of frustrated souls in search of compatible ipkgs!