Dell 2709W 27" for gaming

Hi,
I’m sure this has come up before but I couldn’t find the thread - I’d like to upgrade my 22” screen (its starting to have issues, green lines etc, and its time to enjoy a bigger screen!)
I’m very keen on the Dell 27” 2709 – I can find it for £375 (refurbished I think – though the site says new but with 30day warranty…)

I’ve seen a lot online about the lag- has anyone tried it out on FPS and seen an actual issue. I game a lot – basically play most games but am obviously most worried about FPS as have got more and more into online FPS (CoD4 and Unreal 3 right now).
Is this going to actually cause me problems – if so, any recommendations??

Thanks,