Some months ago I overcame my resistance against software sounds and installed Garritan Big Band. It lay idle for months again, but finally yesterday I connected the Roland A500 controller and tried it (it is used with the Aira player).
The good thing was, even without any extra audio interface, I was able to play the trumpet I loaded into channel 1 without any latency.
The problem: the volume of the trumpet didn‘t change with key velocity. I had to use the mod wheel.
Today, I googled the problem and just found others with the same observation. In a forum it was explained that with Garritan, key velocity IS detected, but only used to change the attack from soft to sharp (which makes sense, as you can play a note quietly and nevertheless with a sharp attack and vice versa e.g. on the trumpet). For volume, you have to use the modulation wheel.
But if that can‘t be changed, it‘s a problem for live play, as mostly you don‘t have your left hand available to do the mod wheel control.