I know of at least one person on my server that consistently clears T5 with a PS3 (I believe he's a BRD). I am a PS3 user myself and was able to get to Twisters consistently, however, me dodging Divebombs wasn't nearly as consistent... Thankfully I'm a PLD and have Tempered Will. I was getting frustrated so I hopped on a PC, and not once was I hit by a single divebomb in our 20ish attempts (and our first kill last night 15 minutes before maintenance too!).

Take it as you will, but I'm sure my reaction time didn't increase overnight. I could notice a significant difference being on a PC in all aspects of the game. Is it possible to clear T5 on a PS3? Absolutely. Will it be more difficult on you and your raid? Hate to say it, but probably yes.