The biggest problem with Blu-Ray is the movie studios. They are so worried about people stealing their products that they go to increasing measures to protect their product, even at the expense of alienating the consumer. All of this extra crap is a problem with almost any Blu-Ray player, since things are constantly changing and have to be fixed by firmware updates. I've only had a few Blu-Ray's that wouldn't play on the Oppo and they were all ones that were just released. How many DVD's have I run into that wouldn't play on the Oppo? Zero! And I watch more DVD's (from many regions) than I do Blu-Ray's.
Now, I've had the PS3 longer than the Oppo and haven't had any problems ever with a Blu-Ray not playing. Though the PS3 won't play PAL discs or discs from any other region, which is why I got the Oppo. If you want the most stable Blu-Ray player I say it is the PS3. If you want a standalone player that pulls the most out of any optical disc you put in it and is 98% as stable as the PS3 then go with the Oppo.