Something to keep in mind: HVM is generally slower(even with VT-x) than paravirtualization...It's not by a huge amount, but you'll definitely be seeing higher IO latency. While this is a neat hack, you're paying more and getting poorer performance.
HVM is generally slower(even with VT-x) than paravirtualization
Not in this case. The problem you're talking about is with emulated hardware; EC2 uses paravirtual devices with HVM, so the performance there is identical to completely paravirtual instances.
