Thunder Taran or Thunder Orkan Lancelot?

I have 2 Lancelots.  1 is an Ancil/Taran and the other is a Thunder/Orkan.

If I had only 1 Lancelot, then I'd go with the Thunder/Orkan.  I've used the Thunder/Taran, but that build runs into problems with the Thunder/Orkan Lance, the Plasmahad, and the DB Griff, as it can't kill these opponents fast enough and it will get seriously damaged even in a win.  Please not that a DB Griff can't kill an L12 Lance outright, but it will if you allow its Orkans to continue to pelt you - which the Thunder/Taran version will allow since it has a lower DPS than the Thunder/Orkan.

I'd stay frosty with the Thunder-Orkan Lance, problem is, it's reaction time is a bit off when facing a diving or fleeing Griff. But you can melt with ease and finish with a BANG! Advise you fire inside the Ork strike range, Lances wingspand causes a gap in where your ? will be hit if not. With a Thunder-Taran Lance, you and skeet shoot a Griff flying through the air, track a Stalker ruining away. All depends on your anchor use of the lance. I've run 5 Lances for 4 months, three are Thunder-Tarans.

Good for advancing against Carnage, Fujin, and or anything without physical shields or rockets on open maps like Yamatu & Cannon.  Plus if they don't look very close Advancing Rhinos, Gary's Gallahads & Ancilots might assume you can't hurt them from 600m out and leave their flanks exposed.  Not the most useful setup in most situations but when it's the right circumstances it's legend.

I've run all the various combos, and my answer has changed over time.

Today I'll typically run 1-2 Lance in my active hanger, either 1x Ancile Taran, 2x Ancile Taran or 1x Ancile Taran, 1x Thunder Ork.

A month ago I often used the Thunder Taran. I find it a bit better in open spaces- the extra range of the Taran slightly compensates for the Lance's biggest weakness (speed) by helping it get into action sooner. I no longer run that combo, however, due to the prevalence of Ancilots in Top. Against Ancilots I find Thunder/ Ork far more effective (thunders fired first to kill the shield) allowing you to escape with minimal damage as opposed to the near even matchup with the Thunder Taran. However I find the Ancilot more effective still, not for personal damage but for team victory. Dropping a Taran Ancilot first and taking it to center (on nearly every map) is an ideal way to gain a strong positional and team advantage. I find it tends to rally much of my team with me and helps us adopt an offensive posture. Currently my preferred tactic when running solo...

Zeus Taran isn't my favorite- I prefer Zeus on a Fury or Carnage, and a plasma Galahad will still eat it alive at plasma range.