I have yet to hear anyone functionally say either is better. Both sound like they will work great. Comes down to do you need the extra dx2 features and do you need the electric option.....and what's it worth to you. After several overnight cooks on my UDS and now BW party (both in the efficient cooker camp with the WSM), I decided it was time for a temp controller. Ordered the PartyQ as it was way cheaper, has a specific BW connectors, and does what I need it. I have the Maverick for the remote temp stuff. Either way, I get why you would want either of them!
BW Party - UDS - 18.5" WSM - Mini WSM
Red Weber Master Touch- "Old Betsy"
Weber OTS 18" - Weber Genesis
"Yeah, all those things, responsibility, pressure. It`s a bit stressful. I try and come to terms with it by not thinking about it." - Joe Strummer