OK, yesterday I decided to play some more with GPO (my copy of the full up Kontakt also arrived but I haven't opened the box, and I hear that people are starting to get there GS3 upgrades so I may end up blowing some days playing with that).
Anyhow for jollies I took a rather involed 21-part MIDI file of Stars and Stripes forever that I downloaded of the net and fed it into Sibelius and started loading up instruments in Studio.
I tended to use the "ENS" version of the voices. It broke up horrible when I played. I went back and switched to solo instruments and things got better (other than to really make it sound right, I'm going to have to rescore the drum and cymbal lines to hit the right GPO notes, I don't know what this file is scored for, it doesn't sound right with a GM percussion on those tracks either).
Is the performance breakup problem a limitation of my machine/card or am I simply asking two much? Does an ENS voice take up more horsepower than a SOLO instrument, or am I on the edge of making it work and just got lucky. I also switched from wet to dry when going from solo to ens so I don't know if that makes a difference.
I have to say that I am impressed, this is the first thing I've really played through it that wasn't just me playing "theatre organist" on several keyboards driving GPO directly.