These are my suggestions:
1. PEQ Presets (kick, snare, tom, floor tom, hihat, overhad, bass, electric guitar, acoustic guitar, male vox, female vox, etc)
2. Add FX3 & FX4 as softkey (in QU-16 I have only FX1 & FX2, but how can I recall FX3 & FX4 on faders???)
3. Add the possibility to play and to record in Mp3 format file
4. Add the possibility of “double channel” (ex ch1 & ch2 with same parameters, same volume faders, etc)
5. Add LR Output for playback