i.e. for a fixed budget of $X you'll get a lower speed Xeon compared to a non-workstation processor. Or when using comparable clock speeds the Xeon will be more expensive.
Not certain that multi-threaded performance would make Xeon any more attractive by cost, performance, or otherwise. In order to do so there would be a need for the numbers of cores typically provided by multiple processors or the wigged-out insane ones (12 - 18 core per processor). But for day to day engineering work anything beyond 8 cores (high end gaming processor) isn't going to see much use.