Soundcrafts Si expression has the very same Function as the Si Compact series,
and their both built in "live sound/Touring in mind"
however with the help of the Expansion Slot,the flexibility are opened,.
Ex: you can add a
*MADI card for expanding the Inputs and outputs / Digital Snake/stage box / multitrack Etc etc etc
*USB/Firewire/Optical card for Studio recording/Live recording use thru Firewire you can capture 32* inputs/tracks with the help of computer base DAW
though we already own a Si Compact 24 and had a Firmware issues,but when the V2.0 firmware
came along,everything Goes Sweet
for me Si expression is the best option