people get too fixated on the number and forget that it ultimately comes down to what's going on inside the processor.. just because you can brute force clock speeds doesn't always make it faster. just look at bulldozer even at 8Ghz+ most modern budget tier cpu's are still faster than it from both AMD and intel stock. i mean hell just take a 4Ghz P4 and put it against any modern AMD or intel chip limited to 4Ghz and the single threaded performance difference is pretty insane.
If that's the case, I wish the manufactures would come up with a better type of spec to compare one to the other. It would make it easier for those of us who don't have time to do huge amounts of reading on the subject and would rather just look at the labels and buy so we could get back to work on our actual use of the computer.