T51-b is just 5 DT higher than ranger armor/reinforced mark 2, and it slows you down even more. On that subject, I am a bit disappointed in Power Armor's low effectiveness across the board. I know of only two way one is an obscure and long quest line that is triggered by doings stuff nobody really seems to know about, the other is relatively easy but can still be missed.

The only real difficulty is getting the training. The others you have to earn with high level quests (killing the Van Graffs before being at least level 15 must not be feasible). Plus IIRC its only BoS armor that just lies around waiting for you, in pretty hostile environments, and wearing it is a good way to get shot by the game's most present faction (that should definitely go away after you establish truce, I agree). Yeah, if you know exactly where to look you can get power armor easily, but that is also pretty much true for the first two games too (rushing to BoS or navarro to get it was only made hard because of the need to reload after impossible random encounters).

Fallout new vegas all armor