Real World Tests:
For our real world tests, I decided to check some file transfer speeds. We read(and wrote) from a 4GB RAM disk which was pretty much the limit as I had just 8GB. We use a RAM disk so that the other drive does not become a bottleneck. I used a 3.5GB compressed file for these tests and measured the time to transfer. These are not perfect tests as its too short a test, but the times should give you an idea of things.
So the real world performance seems to be on par with the SP 920, with only a marginal difference. I think with performance closing in so much, this test has somewhat lost its relevance and I will need to probably use something else.