Xeon should be better, and Im sure you know that. They are colder than the common cpus and they are supposed to do higher clocks also.

About Hyperthreading, as far it doesnt put up your temps high, you should use it. That is for sure.
And also take HT into account if you are going to use you cpu for video/audio encoding, etc. Because it becomes useful, it get down your times in a really notiaceable way.

Taking all that things considered, Xeon would be better whatever you do.