Bottom line, Gear =/= Skill, Skill = Skill, gear just helps that already preasent skill be more effective.

Speed Runs every where work just fine. It all comes down to the synergy factors.
1:Is the DPS high enough?
2:Is the Tank holding Agro properly?
3:Is the healer keeping up with the dammage you're taking?

Apply those three points and any dungeon can be speed run. The boss Mechanis even fall under those three principles.