OCCT is ok, but CPU-Z shows core voltage and speeds too, and Real Temp and Core Temp show temps. Prime95 allows us to customize the prime test in any way we want. It allows us to select any FFT size, or even a range of FFT sizes. We can also tell it precisely how much memory we want it to use right down to the megabyte. We can also tell it how long we want it to run each FFT size for (default is 15 minutes).
Also, with CPU-Z, Real Temp (or Core Temp) and Prime95 open, the total amount of consumed resources is less than OCCT by itself. For me, OCCT consumes 39 MB of memory, while the combined total between CPU-Z, Prime95 and Real Temp is only 8.3 MB. Plus, I can open all 3 of my preferred programs much faster than it takes OCCT to open by itself. I know that this isn't a big deal, but it is to me.
So personally, I prefer Prime95 combined with CPU-Z and either Real Temp or Core Temp.
If I want Linpack with AVX, then I go for "LinX with AVX". Just like with Prime95, it takes just milliseconds to open.
Edit: I just tried OCCT 4.3.2 because I have 4.3.1 and for some reason it isn't opening. I'm less impressed by OCCT than I was before. Now, not only do I have to wait several seconds for it to open, but now I have to close a window that's asking for a donation, and then I have to close another window after that with some message saying that it's not free for commercial use.
Edited by TwoCables - 11/30/12 at 1:55pm