FWIW, the LMAX Exchange currently uses Oracle's HotSpot JVM, but they've announced they want to switch to Azul's Zing. I guess my overall point is that the GC

FWIW, the LMAX Exchange currently uses Oracle's HotSpot JVM, but they've announced they want to switch to Azul's Zing. I guess my overall point is that the GC guarantee in question is an upper bound. It's perfectly acceptable for a financial application to only deliver x ms latency 99.9% of the time. Also, the JVM is only one component in the stack. If you aren't using a real-time OS kernel, you're not guaranteed any maximum latency anyway.