From your post I assume you do not play keyboards/synth's.
In that case I would completely go software.
You need more as cakewalk though.
I would do following;
Upgrade to Sonar (because of the plug in synths and better audio routine)
To expand you might look at;
reason
acid pro
fruity loops
reaktor
vocoder software (several choices)
You need a fast PC/Mac and a pro-audiocard.
(preferable no soundchip in mainboard)
Note:
I would keep the ex 5
Fred
_________________________
Keyboards/Sound Units: Kurzweil 2600S, Roland VR-760, Acces Virus C, Roland G-800, Akai AX60, Minimoog, Machine Drum, Roland R8-M, mediastation x-76