I still need to play DQIV and V, though I have the ROMs I feel it would be better to pick them up; since I usually only own ROMs of games that never made it here or I already own. I have strict pirating rules...
I've always felt that if you weren't going to pick up the game anyways ROMs are completely legit. There are several titles that I would never had bought if I hadn't played the game for free first. But then again I am the type who will by a game after I have beaten the whole thing and just have the physical copy sit on my shelf unopened.

I was going to give them a spin on ROMs a little while ago, but damn Sony took away PS3 Linux support so I can't play them on my PS3