mrk
I would advise spending £30 extra and getting the G.Skill Falcon or the OCZ Summit or the Corsair rather than the Agility. The G.Skill Falcon is nothing more than a rebranded OCZ Vertex (Indilinx), the OCZ Summit and Corsair are more or less the same drive too as I understand it, the new Samsung model.
I did a lot of reading on the subject and just recently purchased the G.Skill Falcon, I'm very pleased with it so far, very fast, silent, cool and silent ...did I mention silent

...no more vibrations! (that'll upset the Beach Boys) ...it makes Windows 7 incredibly snappy, as you would expect.
As I understand it, the main differance between the Agility and the Vertex, which both use the Indilinx controller is that the Vertex always uses Samsung Nand Flash Cells, the Agility can use anything really, so it's cheaper due to this. So it might be a blindingly good buy, on the other hand, you might wish you had spent an extra few £'s and got a 100% known quantity.
However, if you stretched all the way to within a hair of £300 for the OCZ Vertex it's self (rather than the G.Skill Falcon) ...I'd say you might aswell just go the rest of the way and buy an Intel G2, at which point you just spent a cool £100 more than the Agility you originally proposed. So I suppose it's upto you to set that hard and fast limit somewhere
I personally set out with a figure of around £250 in mind for a 128GB ssd, I spent £268.99 in the end, but after doing a lot of research I believe that it was ultimately worth it over the £254 OCZ Summit, basically it came down to £15 more for something which consistently benches faster than everything except the Intel and is firmware upgradeable and is said to be able to support TRIM in the future, although weather Indilinx actually do come up with some Firmware to support this automatically under Windows 7, no one is quite sure yet. The Indilinx based G.Skill Falcon and OCZ Vertex (presumably the Agility) can use a tool called 'Wiper.exe' though, which basically runs a manual TRIM command on the drive. I have not heard of the Samsung based drives having a similar tool to be honest.