Is it just as easy to buy the no-HD 360 and add an HD? Does it come with a CD which will allow me to format it and install the OS?
Otherwise, what features on the PS3-20 aren't needed? The mem stick slots? It's not the glossy finish of the PS3-60, it's the matte finish. I would expect the PS3 to use SATA-II while the 360 uses SATA-I. Does anyone know for sure? Does anyone know if they are 5400 rpm models? I would expect them to be 5400 rpm models for reliability.
I think two things are lacking in the PS3: PS2 mem slots ($15 for a cable adapter) and rumble. If they could have made a no-HD model with mem slots and sold it for $399, maybe more people would have picked it up, if only for the Blu-Ray. But as it is they are losing $300 on the the '20 model and $250 on the '60 model. Which probably means that they'd be losing $400 on the no-HD model.
What I see as the real culprit, though, is the lack of rumble. (Well, that and the non-inclusion of an HDMI cable, if what you are selling is HDTV.) Some people may have wanted to be warned that they were hitting the gravel when playing a driving game, but as an RPG'er I really liked the rumble as a warning of upcoming danger. For Sony, with all of its money, to not pony up and pay a few bucks to license rumble, in unconscionable.
Make no mistake about it, the price isn't "just" $600 for the PS3-60. Add the HDMI cable, the extended warranty (which probably matters more for the 360), 1 game, add ~$100 in taxes, and you're talking about $850 to walk out the door. $850...
(But at least it has wireless internet which would cost $100 more on the 360. If people have their cable box near the TV, and if the cable box has an ethernet port, then wireless is moot, in most cases. Then consider that many new homes have ethernet ports near their cable input. Me, I'll save the $100 and put a $15 50' ethernet cable under the carpet or along a wall.)