I only tested it once, but yes perfomance will be "near" bare-metal. (like GPU -> 95-99%)
Sorry to ask you again, just to clarify... you tested once doing a SSD passthough and got 95-99% of performance in comparison to bare-metal? Because if that's what you meant, that's absolutely perfect for me! (using QEMU/KVM caching/improvements?)
Also when you mentioned 50-70% of bare metal performance, were you referring about using vdisk running on the cache pool? On this percentage did you included the caches and other improvements QEMU/KVM offer?
Thanks!