You have to keep in mind that you get what you pay for with Xbox Live. I have no idea how Sony's operating its Playstation Network, but if they've kept their laissez-faire attitude about the whole thing from the PS2, then it must be the same nightmare from before. I have bad memories of horrible glitching and lag from the later months of Socom II, a damn good game I must say.
Xbox Live is around 5 or 6 dollars USD a month, or 50 dollars USD for 13 months (at least in the U.S.). Anyone who's played an MMORPG knows how beneficial the monthly fees are, as it goes towards system maintenance, rule enforcement, updates, patches, fixes, and server maintenance. Of course, not all games online are perfect on Live, and that really depends from Game to Game. Rainbow Six: Vegas 2 had some pretty horrendous lag issues on both consoles, possibly because Ubisoft left the users to host their own games.
On the whole though, I've never experienced the massive glitching that I did in Socom II or in quite a few PS2 games, and seeing as the structure of the PS Network doesn't seem to be at all different from the PS2 online system, I can only assume what kind of shady gaming is going on.
As for 360 exclusives going to the PC, that is true. But PS3 exclusives go to the 360 before they go to the PC.
It really depends though. If you just want to play offline mostly, or only plan on going online a few or so times (and can spare the money), the PS3 might be a good choice. If you plan on going online a lot though, a 360 is going to be the superior choice. Yes, it has a small fee, but it saves you too many headaches in the long run.
Also, one must be careful on giving technological superiority gamewise to the PS3. Yes, the PS3 consists of far superior hardware, but quite a few games are clocking better FPS on the 360 than the PS3. The greatest example of this is GTA4, which has been recorded going up to 30-31 FPS against the PS3 version's 25-26. Just some food for thought.