Ok, each has their own merits as you see. I can give you my experiences, however.
I have the Asus single slot (like the MSI). The cooler works fine as long as you turn the fan up to 55%, but that is fast (5000+ RPM) and I worry about how long it will last. Also, I originally had that MSI, but it had a short in it and was DOA. I wouldn't consider the single slot coolers unless they are cheaper.
As for the sapphire, looks fine.
And for the Asus, I've never heard that about the drivers before. That would be really bad if true. Like I said, I do have the Asus, but not the "Top" version. Asus does include a couple extra OC/fan programs, but they don't limit the drivers.
I'd probably go with the Sapphire since it is the cheapest and should be easy to OC up to the Asus levels. The Asus is quite good too. Depends on how much you want to spend.
Update: While gaming it seems to crash. Could be a over heating problem. WMC on vista 32 dosent work, could be a driver issue. WMC for windows 7 64-bit works great, same driver. At this point thinking i should go back to Nvidia even if a little more $$$.