Hey all, I just wanted to know if there is any real difference between the ps2 and ps3 version for Ratchet and Clank 1,2 or 3

For Ratchet & Clank (the original), PS3 is faster due to shorter loads. There's also two exclusive glitches on the PAL PS3 version where you deal damage every frame with the Pyrociter (useful for the NG categories) and Drek Skip where you do some file manipulation or something (only applicable for ng+).

For Ratchet & Clank 2, the PS3 version is based on the Greatest Hits version, which means for the NG+ categories you can't do a lot of movement that's required for a top time, and you can't do Ship Shack glitch which means you'd lose time in Any% also. RaC2 on PS3 is pretty much useless in terms of speedrunning.

For Ratchet & Clank 3, the PS3 version loads slower but everything else works. Clipping with the Mega-Turrets is a lot more difficult though, so if you plan on running on PS3 you might need to fiddle with that.

tl;dr, you need the ps3 pal dl copy for a top time in the first rac, rac2 ps3 is useless, and rac3 ps3 can be ran on but loses minutes to loads. This isn't 100% all version differences and I might've missed a few things, but this is the gist of it.

I have a rough list of PS3 differences for Ratchet 2 and 3.
You only need PAL for Ratchet 1 if you want to run any% or all gold bolts. Drek Skip works in all PS3 versions but not PS2.
PS3 Download is faster than PS3 for the whole trilogy due to much faster loads than PS3 disc.
Ship shack glitch does technically work on PS3 but it's not RTA viable. Any% would be a bit slower but not too slow depending on raritanium RNG since the loads are a lot faster than PS2.
NG+, No IMG and no specials would be significantly slower but all plats would be unrunnable since ship shack glitch saves way more time than in any% and the clip with the charge boots in Boldan doesn't work on PS3 which loses the most time in all plats.
Ratchet 3 is pretty much the same other than longer planet loads, QSP can't be switched off and you can't pause while the game is auto saving which takes longer on PS3.