PCIe GeForce 7950GT ExTreme vs. 8600GTS?

OK. I want people's opinion on this... which card is better? Two of whichever one I choose will be used in SLI mode (see http://mikemchargue.com/2006/09/second-life-and-nvidia-sli.html ) so I can run two together to make SL graphics run faster. Both of these are 512GB DDR3 VRAM cards, both take up only 1 card slot, both are "SLI Ready" (as opposed to "Supports SLI" and both are each available for under $200.

I'm just wondering, because while the 7950GT ExTreme is older, it has 256-bits, while the newer 8600GTS is newer but has 128-bits, and benchmarks show the 8600GTS as slower than the 7950GT.

I am going to use them with this board:
http://www.newegg.com/product/product.asp?item=N82E16813128073
...this memory (or similar memory with a lower Cas Latency):
http://www.newegg.com/product/product.asp?item=N82E16820145184

...and a 500GB IDE and/or SATA 3.0GB internal hard drive (these are available out there for under $100 each with a little luck)

UPDATE: See comments below, looks like the (512MB) 8800GT may be better than the 7950 ExTreme, but is it really?

7950 will eat the 8600 for breakfast lunch and dinner.

If im not mistaken, the 7950 is dual 7900 chipset is it not?

Regardless get the 7950, or if you can find one 8800GT.

The 8600 is a pedestrian card, even in SLI mode it isn't that great. For SL, SLI won't do much at all for framerate but will allow higher AA filtering. Running a couple of 7950's in SLI is the equivalent of running 4 7900s and will blow the doors off a pair of 8600s. For the same money though you can buy a 8800 GT and get a bigger bang for the buck and not have to buy a monster power supply to power two 7950s.

Get a single 8800GT, SLI is very overrated, and an 8800GT will perform pretty much as well as SLI 7950's anyway.

Yes SLI is overrated.
You'd think if you have 1 graphics card you have 100% power, and if you have 2 graphics cards you have 200% power.. Not the case, its only like a 10-20% increase, pointless really.

Avoid any mid-range cards if you have the option to get a high end.
7950 or 8800GT is what you should go for, they should both be roughly the same price range.

I have 2 x 8600GTS in SLi, having "upgraded" from 2 x 7950 GT OC in SLi...

I can't see any major difference or benefit from this "upgrade", but, then again, no degradation either.

I wish now I'd not bothered moving from the 7950's to 8600's but instead either:

1) kept the 7950 GT OC's (which are pretty good GC's)
2) gotton a pair of 7950GT ExTreme's
or preferably, 3) gotton a pair of 8800 GTX's

Can't go there. The 8800GTX Is well over $200, and $200/250 is my cutoff point for spending money on a (super fast) video card. I think it's ridiculous to spend the amount of money needed to buy a whole new decent computer (from parts) or for a PlayStation 3, simply to get a video card. I don't believe anyone should expect to pay more than around $200 for one at this point. Also, the 8800GTX takes up two slots instead of one. Not good. The 8800GTS has this same problem.

Now, it looks like the 8800GT is nice because it's around $230 for the XFX (my favorite video card company) model:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&Description=GeForce%208800GT&bop=And&Order=PRICE

I am just wondering if "HDCP Ready" means this card will try to block some video content I try to play, which would be really lame.

Also, to the people/person who said SLI is not so great, this SL user says it doubled his frame rate. That's significant, isn't it?:
http://mikemchargue.com/2006/09/second-life-and-nvidia-sli.html

I have a XFX GeForce 7950 GT ExTreme complimented with an AMD dual core CPU. everything in windlight is set to ultra, with a drawing distance of near 400 meters. FPS stays solid on the better sim servers.

I chose this particular model as the system i built is also a media center, so i needed quietness and lower-than-average power consumption.

Well, on my rig, I can comfortable run SL using the Windlight viewer, and get really good, acceptable frame rates. Sometimes the SL FPS Meter is pegged at the top (can't give me any more FPS!) ....W00t!!!

Also on my single lil' 8800GTS I can comfortably run Crysis with all graphics turned up to High.