I practically stole a 2.13 pre unibody macbook the other day for $500 on CL, and I have to say I'm pretty impressed with it.
Admittedly, though the screen is not as bright as on my uni mb, I don't think I'd notice unless they were side by side. (It doesn't appear to have the match screen brightness to ambient lighting as the uni alum mb does, either.)
BTW, the genius replaced my topcase fascia (in front of the keyboard towards the magnetic latch) in under 20 minutes. He mentioned that the older whitebooks had a problem with the cracking, and they had some thicker, more durable replacement pieces in the shop that will hopefully prevent that problem from happening again. The five hour plus replaceable battery is freakin' sweet.
Honestly, I would think that the refurb 2.13 mb on the apple would be adequate for most people unless they had to have a seven hour battery or backlit keys.
I also checked out the plastic unibody mb displays at my apple store while I was there, and they didn't appear to be scratched or damaged. Nice looking machines, but I think I'm still happier with my five month old prior gen for half the price.