Is Gig Performer + vst's really a viable live solution compared to new synth?

Wow…this software is amazing…thank you Eza…I found the link…followed these clear steps from ‘PianoPaul’ below…learned I needed to allow automation in Omnisphere…and away I go…a working Tremolo aftertouch …on my good old Xp80…feel like I’ve just discovered a whole new world!!

Thanks everyone…the mighty Roland Xp 80 now sings and dances like never before;)