I'm still auditioning sounds in GPO, but I haven't been able to acheive a convincing stacatto with a natural sounding release in the solo instruments. The solo violins in particular - the attack seems too slow to simulate a spicatto attack. Some of the demos I've listened to seem to acheive a more agressive attack. I did install the update, and I like the new aggressive instruments, but the solo violins didn't seem to get the same treatment. Am I missing something?
Also check out the "Length" parameter, which controls the release time. Lowering this parameter also dramatically improves the staccato effect, since staccato requires both quick attack and quick release.