Apparently the wife got free overnight shipping, so I got my Vibrant last night. It was NIB, and running 2.1. So no problems rooting and installing cwr. I played with it for a few minutes, plugged it in and left it to charge.

4" amoled screen (800x480), 1ghz cpu, 512mb ram, 16gb memory (~2 for apps, ~13 for storage), 2gb sd card included.

There's a huge number of custom roms out there to flash. Pretty confusing at first. CM7 is still a beta, so I stayed away from that for the time being. I went with Bionix V 1.3.1. Flashed the new rom easily.

Very speedy no sign of any lags so far. This afternoon I switched over to Zeam laucher and the OverStock kernel (undervolt, no oc). Nice and speedy, BLN works to show the button led when there's a notification. Also unlocked it using a free app from the market (an old AT&T sim works, no service though)

Pretty happy with performance so far. GPS seems OK (not fantastic, but OK). I don't think the camera is as good as the N900 (but does record 720p video nicely). The screen is pretty awesome, great color and viewing. Capacitive is taking a little getting used to, much more sensitive than what I'm used to. 4" size is nice as well. Plays 720p video nicely as well.

Size wise, it's a little wider and taller than the N900, but only about 1/3 as thick, and probably less than half the weight. It almost feels like a toy in comparison, doesn't feel as sturdy either (probably due to weight). Doesn't get as many bars as the N900, but I don't know if that will be a problem or not.

Pros: screen, bigger battery, faster cpu, wifi calling works.
Cons: less memory, no h/w keyboard (big fingers = harder to type onscreen), single speaker, no stand (use that occasionally), no fm transmitter (occasional use), no multi-tasking.

Biggest con: will cost $15/month more for data.

Overall, I like it. Probably put my sim back in the N900 for a while, so I can continue to play with this and not loose my phone.

I'll try ubuntu a little later this weekend.