Well overclocked I don't know, but out-of-the box single-core performance completely sucked. And in 2007 not enough applications had threads to make it up in the number of cores.

It was fun to play with but you'd also expect the higher-end desktop to e.g. handle x264 videos which was not the case (search for q6600 on videolan forum). And depressingly many cheaper CPUs of the time did it easily.