I put the 240 Mercury in my last Macbook Pro and it was fantastic, tests showed it always hitting 235 Mbp read and write.
I have the apple ssd in my current Macbook Pro, ( I need 500GB, btw OWC havent shipped a 480GB as yet) and I can at best get about 180 Mbp read and write, which is still great compared to a 7200 rpm HDD.
But having had the OWC one I know things can be faster than the stock Apple Toshiba Unit.
On another note, customer care from them was up their with Apple, I had to return another SDD and they reduced the restock fee from 15% to 5% which was very kind considering the drive was used.
The sandforce controller really does shine, you will not be disapointed, I only wish they had the 480's available to ship.
Btw I was booting in 17 secs on the OWC, and I boot now on the same system with Apple in about 22 secs, not that important I know but you feel that snappiness on the OWC in everything you do, good choice sir!
Ocw changed their controller in August 2011 to sandforce 2282 with a new Toshiba toggle. I've been using Mercury Pro extreme 6g 240gb in my new 17' MBP and it works beautifully. fast as lightening. Expensive but worth it. 11 second start up to open browser. 5 year warranty.