Ps1 games on playstation store

So I've seen a handful of games I wanted to buy for ps1 on the playstation store for ps3. Any differences? Thoughts? Comments? Thanks!

@vintage90s: PS3 PSOne emulator is great, never had an issue with it.

Can also just play PlayStation discs on a PS3 so if you find cheap copies of those old games? I'd advise that over the PS Store.

They work perfectly fine. The only real problem is the emulated analog switch, which is unintuitive and cumbersome to toggle. That and the poor selection they have on offer and the fact they don't let you play your purchased games on the PS4 as well.