BNK-3R, like a lot of bosses, can be easy if you find the right positioning. Otherwise, it can be hard. Kind of like how fighting a Constructor can be easy if you find good cover right from the start.
Beat the game yesterday and the end-boss is the same. There are places to stand where you own him without problems. I think they did it on purpose, so people don't feel like it's impossible to win solo.
True Vault Hunter mode is damn hard. I've been basically 2-hit killed a few times already. Pulled a group of Bullymongs and TWO Superbadass types spawned. One leaped over a ravine and with one hit crushed my shields and knocked me down to a sliver of life. I came back and killed them, but it was a harder fight than most bosses battles on regular. Had to use most of my life-stealing grenades and even then I only won because one of them got stuck on the terrain. Also, opponent's shields are a LOT harder to deal with. You pretty much have to have a shock weapon. The biggest pain, however, are the armored Psychos. I still don't know how to deal with them except by using my cooldown, they're incredibly hard to kill.
Mechromancer I got to level 8, seems pretty nifty. Like the guy from Gearbox said, it's kind of a simpler path. More tank-and-spank centered. Not sure how it will play against some of the stronger bosses, though, or on TVH mode.
