I'm pretty sure that gummo on SRK has modded this pad before.
Wired PS2 pads are just as good as their ps3 counterparts
The only difference is probably the R2/L2 as they're digital on a PS2 but analog on a PS3
How you hold a stick can definitely play a factor on how you perform on a stick. Certain holds require the exaggeration of certain muscles which can make some holds more comfortable than others, i.e. a wineglass grip tends to stress the wrist and thumb while something like a bat top hold will stress more movements from the forearm.
Developing muscle memory for movements is another factor on how you perform on a stick. This sort of practice takes more than hours to get used to and perfect.
Ultimately the time you put into practicing with a peripheral positively correlates with your performance with said peripheral.
Its okay to prefer pad if that's what you're used to. The best thing is to try out different things to find what you do best in.