^Depends completely on how comfortable you find the controller to be with FPS games.It's only a matter of getting used to aiming with controller rather than keyboard & mouse.I have seen many people who were PC gamers & after getting Xbox 360 or any other console have become very comfortable with FPS games on it.I personally couldn't aim straight in Project Snowblind & Black which were the only 2 FPS games for PS2 that I laid my hands on.But then again I don't care much about FPS being played on PS2 as for that I have my PC.
You'll have host of other titles besides the FPS genre to feast your hands on the PS2.Considering that you'll have a good time with the PS2.I was researching on a couple of must buy games for the PS2 the other day & found that there were so much more than FPS on this console.You'll have survival horror games like Forbidden Siren,Clock Tower,Fatal Frame & Silent Hill series.Awesome platformers like Ratchet & Clank series & Jak series.The almighty WWE Smackdown titles.Mortal Kombat Armageddon which is only available on PS2,Wii & Xbox.God of War which needs no introduction.Tekken & Virtua Fighter for arcade combat action.Ace Combat series which again are great flight combat games.Can't ignore Burnout series now,can we?
And the list won't end.You'll have host of other titles to go for.
Don't merely judge it by it's weakness on FPS games controls.It still has a long life & isn't dead yet unlike the original Xbox.