I have a 512GB Kingston SNVP325-S2/512GB, and this is a quote direct from their website (in reference to the SSDnow V+ series):
Features:
* Innovative Uses MLC NAND flash memory components.
* Silent Runs silent and cool with no moving mechanical parts.
* Shock Proof No moving mechanical parts so the SSD handles rougher conditions.
* Supports TRIM Enhances device wear leveling by eliminating merge operation for all deleted data blocks
* Supports S.M.A.R.T. functions
* Guaranteed 3 year legendary Kingston warranty, 24/7 tech support
* Cache 128MB onboard cache
* Garbage collection feature Enables high SSD write performance even when operating system does not support TRIM
I use this drive heavily and have never seen any slowdown after a little more than a month's use. I copy LOADS of data to and from this drive constantly, and have expected a greater slowdown than I've seen (especially considering I haven't seen ANY slowdown). Granted, this is a $1400 HD, but you can still pick up some of the smaller capacities for something reasonable. From what I understand, ALL the SNVP325 models have this built-in GC feature, based on Toshiba's chipset, AND is one of the few drives to support TRIM right out-of-box. Beware the SNVP225, based on Samsung's chipset that does NOT have this feature.