To each his/her own. We don't use potty pads, but I have absolutely no problem with people who choose to use them.
I prefer for Levi to be outdoor-trained -- but we are fortunate to live in a pretty mild climate, and someone is available throughout the day to at least come home and take him outside to potty. If we lived somewhere cold or if he were alone for 8 hours straight - you can bet I'd be considering pee pads.