You have to remember that the majority of those comments are from dummyheads.
I was helping someone else with a choice on that and read a lot of those comments. What they seem to be complaining about is that they think the default speeds are too low, typically during times the card is idle and that it doesn't kick in soon enough under load. The exact same
issues were around for the single slot cooler design on the 7800 GT. It does run a little warmer than some cards. It's fans do run a little higher when idle. But I honestly wouldn't worry about it unless you are having trouble with the cards.
What people in those threads seem to forget is that the manufacturers' aren't going to release cards which are incapable of cooling. That's just dumb to think that. If everyone had to go to an external source to tweak their settings or suffer from overheating issues the RMAs would be through the roof because most peeps just don't know how to do that.
If you are really concerned about it I'd recommend two things...
1- Get an 8800 GTS G92
instead; basically sex in a box there.
It's a little more powerful, isn't a whole lot more money, kicks the butt of the previous GTX at about 60% the price, and has the standard double-wide cooler which pushes the heat outside of the case.
2- Get an Evga 8800 GT
card. Evga cards are designed so that you can update the card bios. Updating the card bios would update the manufacturer default settings with fan speeds. So, if they truly felt that the card's fan wasn't kicking in at the right temperatures, they could adjust the bios and put up a post saying, 'hey everyone, try out this bios if you are having issues.'
PS - Hum, my bad on the thread. Looks like you are right in that it doesn't, or did not ever, exist. I think I may have held off on announcing it because it was too early and too much info for most peeps to need and then never got around to actually announcing it later.
But yeah, no worries, you will be able to use a PCIe v2 or even PCIe v3 (graphics) card in a PCIe v1 slot and it will work. It will work 'gimped' compared to what it would be on the higher version, but it won't be any slower than a card native to that type. I don't think there is any current gain for v2 cards in v2 slots compared to v2 cards in v1 slots. It probably won't show any real gain for a while. I'd guess that it certainly won't be much of a gain till v2 slots are mainstream (like 3 years from now.)