The #1 complaint is the bad keybed--say that it is sluggishly-slow (can't play super fast licks--notes don't retrigger as fast as Yamaha Motif or S-series keyboards. Also, I'm hearing that keys often stick as if someone accidentally spilled syrup on the keys...the sticking keys often occur after the keyboard has been transported--not laying horizontally flat.
ONCE the keybed issue gets fixed..then...here is a short list of improvements I'd like to see on the SV-2:
1). Make a "flat top" version to be able to stack another keyboard or midi controller or Laptop.
2). Add real draw bars so to change organ registers.
3). Add a "MIDI ON/OFF" button next the existing "Local On/Off" button. This way you could use the midi-out to trigger external sound modules and be able to turn the Midi Transmit On/OFF on-the-fly.
4) Add a volume foot pedal input that is designed to control midi volume of external midi sound sources. AND/OR add a Volume Knob that is designed to control midi volume.
5). Able to layer/split two different patches and store them as a Combi.
6). Update the Piano sounds to at least be on the level of the kronos (or Motif)
7). Add a bank of vintage MOOG Leads/brass/pads

9) add a bank of vintage MONO/POLY synth sounds
10) add a bank of vintage Oberheim Leads/syncs/brass/strings
11) add a bank of vintage Roland JP-8/MKS-80 Brass/Leads/Strings.
PLEASE!!!