Lack of Work Up due to 98 Base Speed, letting alot of 100's beat it out, and having to fully invest in Speed to beat Haxorus and 95's, mixed EV's wouldn't provide alot of strength. Also, I think because things like Infernape could pull off the set better, using a 108 Base Speed. And a set with DPulse, Outrage and Fire Blast wouldn't work, you should try EQ, Fire Blast, Dpulse/Outrage.
Finally, I think the prospect of a Work up set is somewhat inferior (not outclasses though) by a DD Mence set EQ/Outrage/Fire Blast because it achieves what Work up tries to do on Hydriegon, blast through specialized walls...and where Hydriegon has awful problems without boosting its Speed, Mence can DD to crush most counters (Watch out for SR though).