The Xbox remote is infrared (the IR receiver is next to the memory card slots on the old model 360s), whereas the PS3 remote is Bluetooth. The downside there is that the PS3 remote is probably more likely to eat through batteries, since it would have to maintain the wireless connection. Either that, or it goes into standby after a while of non-use, and you have to push a button and wait a second for it to re-connect. I don't have one, so I can't say for sure, but that's how the standard Wii remote works when you're using it for Netflix or the like.
My 360 remote stopped working a while back. I'm pretty sure it's the console rather than the remote, since it can still control the TV. Just one more thing to add to the list of shit that doesn't work on that thing.
That'd be one more thing to note about the PS3 remote: Being Bluetooth, it's not much use as a universal remote. (I think the newer revision that came out last year does IR as well.)