Durawrite is nothing like TRIM.
Trim is just a command, that tells SSD when you deleted data (ie, this sector is now invalid, erase it). If trim is not present, ssd will work just fine without it but it will wait until something else gets written to the sector you deleted before, before it will erase it (ssds doesnt have any other way of knowing you deleted data -- except ofcourse trim).
Now sandforce works a little differently; it uses compression (which is a part of durawrite). With the space it gains using compression, that space is used as sort of a spare aera for incoming writes (as writing needs erased blocks/pages). Because of that, it doesnt rely on trim very much (as it can be confirmed -- when you slamm it with incompressible writes, after trimming, write almost never recovers), because it waits until the last "second" before it starts erasing blocks. But obviously trim help sandforce to know which blocks are empy, so it doesnt drag them around while doing wearlevelling.
As for 3K, this is an acient drive not worth buying. And besides, kingston is a shady company now, whith all that v300 fiasko.