Hey martiino - what specifically are you trying to do? Settings can be tweaked for UE specific to whether you're running GRs or Nephalem rifts. I'm doing GR60s to quick-level some new gems with UE, and UE is the fastest TX build.
M6 is the most reliable for higher GRs, but it runs slower overall at lower levels. Definitely make sure you're using a goldwrap / boon of the hoarder for TX or Wraps of Clarity with Focus & Restraint (NOT ENDLESS WALK!) for GRs. UE is fast, but it's not a very tough build - you're gonna die to boss & elite abilities pretty regularly - make sure you're using the Awareness passive (Awareness, Cull the Weak, Thrill of the Hunt, & Ballistics for GRs for UE Fire). Once you gear gets good, UE Cold is best for TX - swap Thrill of the hunt for Blood Vengeance and Awareness for Tactical Advantage.
I even use Nemesis Bracers in TX, along with Pride's Fall & Avarice Band in the cube.