Recently I posted a piece of mine called "Elephantopia" that was done with GPO for the oboe and bassoon parts. My plan was to bring in live players for those parts, and this past week I was able to do that. I spent a lot of time refining the parts with GPO, so that the actual recording time would be minimized.
The players that I used are the principal oboe and bassoon players in the Orlando Philharmonic Orchestra. The part was challenging for them, not because it was difficult, but because they are straight orchestral players, and the parts have a swing/jazz style.
Nevertheless, I think they did an awesome job. You can hear both the GPO version:
and the live player version:
at the above links.
I can provide details about how they were recorded if you like. I used Sonar for the piece, and used the Waves Renaissance reverb for the oboe and bassoon parts.