Sorry, yes, I tested my USB 3.0 speeds by copying to/from a 4 drive raid 0 array, and my transfer speeds were always simply the limit of the drive in the external box... I tested with both an old Seagate 320GB drive and sustained transfers of approx 60 MB/s and I also tested with a newer Seagate 7200.11 1TB drive and achieved sustained transferes on the order of 90 MB/s.
In both cases, this was the same rate (approx.) as these drives achieved when they were plugged directly into a SATAII port. So, in my experience, when transfering across USB3, you will generally get a transfer rate equal to the slower of the two drives.
I didn't really give numbers because it will vary ALOT depending on the hard drives in questions, it you are using newer drives, then I would suspect that you would usually get 90 to 110MB/s with some average drives...
Sorry for hijacking the thread...
Dan