VSync does no such thing. VSync caps your framerate at your monitor's refresh rate, and that is all it does. It never "let the card have more hosrepower",
Although capping FPS does often provide more stable FPSes and a card which runs hot less quickly.
(Protip: extend your graphic's card lifetime by always capping your FPS to your monitor's frequency whenever possible - and if not, force it via RadeonPro or the nvidia driver).
Alright, two things.
1) If your GPU is getting so hot under full load that it actualy endangers the card (which would be 85-95C+ by the way depending on the card, anything under that doesn't reduce the lifespan measurably), then something is wrong. You need better cooling somewhere.
2) It isn't the heat that kills GPUs. They have thermal limits built in for a reason. What kills the card is getting hot, getting cold, getting hot, getting cold. That fluctuation in heat can break the solder, which is why the oven reflow method can sometimes revive a dead GPU.
Correct on stable frames however. By limiting yourself to the FPS cap, you help keep the frametimes consistent if you are at or above your refresh.
One other question: the 1ms (GTG) response time seems to apply to the Asus monitor mentioned, but the Acer says 1ms and no (GTG). Is that better? I'm not really looking for a 144mhs, but a response time of 1ms or less. In addition, the Acer has a better contrast ratio then the Asus.
1) All responce times are GTG. They just aren't required to say it.
2) Dynamic contrast is BS. You want colors, you go IPS, not TN.
I also took in account the need for a better video card: http://www.newegg.com/Product/Product.aspx?Item=N82E16814121770
Thanks for the tip KyadCK!
Heh... enjoy. That should do just fine in modern games.
The Tempest does look like a great deal at the high end. However, I don't like the lottery with the refresh rates on it. I think they do guarantee at least 100hz though.
120hz makes a big difference in games that maintain that framerate, and you can notice the improvement even when just browsing websites or doing other basic things. Older games can usually do a consistent 120fps with vsync on modern cards, although FS2 has engine limitations that make the framerate drop frequently even on modern systems.
The other thing that improves games a lot is a strobing backlight (Lightboost or something equivalent), which literally reduces the motion blur down to CRT levels. This makes a huge difference in Freespace and Descent 2/3, more than any other games I have. The slow, steady turning motions in these games (and background nebulas in FS2) bring out motion blur quite heavily, even on the fastest TNs, but they look incomparably better with this technique. I think only certain monitors support it though. It needs at least 100hz to work (120hz or 144hz is preferable), and I'm not sure if the IPS models work as well as TNs with it.
I have an older Samsung S27A750D, which has a number of quirks and is long discontinued, but it's the only monitor out that is 120hz, glossy and supports this type of mode (not Lightboost, but it has a hardware setting that does the same thing). It does have the grainy look in motion common to TNs, but the black levels are better than most IPSs due to the glossy coating.
It doesn't help that they are 100% out of stock. The latest Temptest was out of stock about one week after the pre-order period. Mine is a glossy btw.

Correct on Lightboost. Combined with G-Sync... It's a pretty thing.
I am not aware of any IPS monitors that support lightboost though because I am not aware of any IPS monitors that are officialy 120fps, even at 1080p.