I can't post any screen shots from work (IS blocks everything) but yeah, the C300 still holds it's own in certain areas of performance; that's just the way it is with a different type of NAND on-board. That being said, when you do more overall thorough user experience benchmarks like the HD test suite in PCMark Vantage, the C400 seems to pull ahead pretty significantly. Attached to the SATA3 Intel port of a P67 MSI motherboard, 2600K CPU (non overclocked) and Intel 10.x RST driver, the 128GB C400's I have been playing with pull a HDD PCMark Vantage score of 58000+. The 512GB C400 PCMark Vantage score is doing 62000+ scores. This is relative to the 256GB C300's which I "believe" I had scoring around 45000 at best with the exact same configuration.
If I get around to playing more, I plan to hook up a few C400's in different RAID configuration using an Areca 1880i SAS 6G controller. With 4 256GB C300 in RAID 0, this config pushes around 1.1TB+ sequential throughput. I can only imagine it will do much better with the C400. But hey, you never know. Might suck

. I play with oddball configurations that the engineers don't get to.