Level 184 Demon Slayer solos Zak in 2 minutes

I don't count portal as mobility. With the nerf to drill rush, 4th job mechs in tank mode do have low mobility, even including combat step. A 4th job mech wouldn't be out of tank mode, with the drill rush nerf making non tank training impractical.

Uhm, about Mech training:
-> LHC training = 4th job Tank mode since Cannon + Siege = insanely powerful
-> Everywhere else = Prototype mode + Drill Rush + Acceleration Bot + Punch Launcher + Buffed Satellites => All the way.

A 140-speed Proto Mech + Dash + Rush = Way faster training (Don't forget Punch also stuns) then a fixed-120-speed Tank Mech + Laser, unless the map is really really small (all high-lvl maps are large).

Also, Rocket Booster is about twice as fast in Prototype mode then in Tank mode.

Don't forget, Punch Launcher (611% DPS x 6 @ 500% range) is still quite strong and Tank Laser (902% DPS x 6 @ 695% range) got nerfed hardest of all Mech skills (dpps with critical ring of course).

Also, Mech rush = Warrior rush, so it's not really impractical to use now, besides that, it hits 15 monsters at once now (like warrior rush) instead of 6, very useful at skelegons bottom.

But ok, at LHC, Laser (or Siege / Cannon) wins hands down.