Along with Al's review of the new EVO line you can get a second opinion from The Tech Report about the performance of the new SSD with a fast cache.  The majority of the storage is 19nm TLC NAND but there is an SLC cache sitting between the controller and that long term TLC storage to help with the overall responsiveness of the drive, aka TurboWrite. In the 120 and 250GB models that cache is 3GB while in the larger models you get a 6GB cache.  In their real world testing the new EVO drive is incredible at large file copying though Sandforce drives can beat it in small file copy speeds, likely thanks to the compressed write trickery that controller family is so good at.  Check out the review here and keep your fingers crossed that MSRP is the acual price these drives sell at.

"Samsung's entry-level 840 EVO SSD combines affordable TLC NAND with a server-style SLC cache. We explain the drive's unique buffering tech and explore how it affects performance."

Here are some more Storage reviews from around the web:

Storage