My favorite features would be:
- MIDI through
- punch in / out
- the possibility to edit sustain, pitch and modulation messages
- better sound-quality for the internal instruments
(I´m Cubase-Artist User and so I used the Halion-Sonic sounds,
in my Opinion these are much better than the internal Cubasis Samples) - some kind of VST instruments (like Virtual Guitarist) or at least some useable MIDI loops.
(As some others mentioned before, I would be too willing to pay for some better sounds or some Virtaul Gitarist substitute, or some other special features beyond the DAW basics)
cheers