anyone that has played both (PC % PS3) versions and can give an opinion on the differences?

have all games for PC and ME2 for PS3 but am considering buying the trilogy due to the crappy way DLC is handled on the PC version

I played it for awhile on PS3 and it is hard to look at. PC on max settings at 60FPS or 5 year old console game at 30FPS and less...take your pick.

"Both versions" as in the PC and PS3 or the PC and 360?

I started my Mass Effect career playing on the Xbox 360 when the game was first released. The shitty framerate and other technical hiccups were enough to put me off playing it completely after only a few hours. Later on I bought Mass Effect 2 on the PC upon it's release and enjoyed it immensely. After finishing that game I immediately bought the original Mass Effect for the PC and really enjoyed my experience.

So in short, play it on the PC if possible.

FWIW; you can handle all the DLC for ME3 directly from Origin, no need to install seperate packs anymore.

Not sure if they've added the ME2 DLC to Origin, but I did see some of the ME1 DLC (Pinnacle station?) in Origin the other day (when looking for Omega/Leviathan, which I didn't find at the time (but did later) :P)