7950GX2 Quad SLI on a 975X? ASUS any good? 512MB or 1gb?

Hi friends,

My new Conroe system is about to be assembled.. but my damn VPU hasn't arrived! I looked into the delay, and it turns out that the XFX GeForce 9750GX2 I orderded was out of stock. The vendor, which I will not name, felt no need to tell me this but they didn't mind charging me for it. Well, I raised hell and now they're going to Overnight an ASUS 7950GX2 to me (at $440 total, not a bad deal).

Questions:

1) Is the ASUS product appreciably higher quality than the XFX product (especially considering that I have an ASUS P5W DH Deluxe mobo)?

2) Will ever be able to go Quad SLI on a 975X or will I need an nVidia chipset?

3) I saw in another thread that their system only saw 512 MB of their 7950GX2's 1GB of memory. It was said that this is because it is really two cards, so the system only sees the memory present on each SO -- is there any chance that certain games and applications may only be programmed to take advantage of half of the GX2? I sure hope not!!

Expanding on your answer to my question 2 -- I figured SLI was a lost cause for me. It was a tough decision between nVidia and Intel, but I ultimately went with the 975X due to its better suitability for CPU overclocking. So if I understand you correctly, there exist hacked drivers that will allow for an SLI arrangement on an 975X boards. Where could I get these? Would you guess they'd be stable?

Expanding on your answer to my question 3 -- What do you mean by it not adding up? I certainly plan to use the highest possible resolutions my apps (mainly FSX) will permit. Under normal circumstances, will only one VPU be active? I still feel good about the purchase, considering I got it from a local retailer for $350 before tax and shipping (I'm friends with one of their marketing managers -- I can't imagine getting a deal like this anywhere else). But for all standards and purposes, do I basically have the firepower of a single GTX?