I got macbookpro, 2.3ghz, i7,quadcore, 4gb ram. I just opened the brass on my logic 9 to test.I load 4 instruments, write some partitions and I can play them fine but whenever I wanna change the preset on brass (while its playing), it crashes.
when i read your post, i tried to open only one instrument on brass and tried to run 2 separate brasses at the same time, it also crashes. i just got the brass and still testing. so far im not happy with how the presets sound, they dont sound like the ones on the arturia media page.