So there were some legit uses for a point blank volley.
Point blank volley with ArrowIV missiles is ridiculously awesome and is one of my favorite maneuvers in this game. Nobody ever expects it, so they see me in a slowish Catapult C and they decide to charge to get "to close to use my arrows"...now their torso (usually it's a bigger mech then my cata) is nudged in front of me, so I just dip down and fire.
Yeah, I take some damage too, and maybe the arrowIV has lessened damage at point blank - idk, but it's worth it.
Anyways, about MRMs, they're pretty sweet but I also didn't notice the new max range change. As KingLeer said though, 650m is more reasonable for what is supposed to be medium range. I was wandering if there'd be an SMRM, basically the MRM version of SSRM. I assume not, because I assume that it is not canon (didn't find it on sarna). There was an SMRM in mechwarrior4 though, it was added into the game with the Clan 'Mech Pak.
And yeah, Cata B is pretty damn good, and luckily still available somewhat early even after the new pricing system.