PS1 eboots from PSN vs PS1 eboots from rips

I was wondering what the difference was. I've heard the PSN/PS1 games with multiplayer have adhoc added on (something I would have no idea how to do). I've always preferred making my own rips so I can rip whatever I don't want, but it seems most PSN/PS1 games are being made with pretty good rips. Also, how about those games with known issues when ripped by hand like the Resident Evil series? Are they bug free when bought from PSN?

The bugs are most likely fixed, they probably make a smooth transition to fit perfectly on the PSP. I was just looking at a top downloaded chart and Resident Evil was at the top so I guess they did it right.