As the CRB is one of my recent FAVORITE chassis, and I'm having an absolute BLAST with them, let me offer this...
First, it's relatively XL-safe. Torso-twisting in this thing isn't going to do you much good, and shielding with the arms is downright impossible (unless the enemy is well below and somewhat behind you). You want to spread damage? Like some other mechs with long snouts, just wiggle the nose at it. In fact, just get used to doing that ALL the time unless you're aiming/firing. So yeah, use the XL and let SPEED enhance your ARMOR. A 250 isn't TERRIBLY slow, but I run XL280 or faster. Actually, between the three I have, I run XL280, XL300, and XL320 (or is it 325?). So seriously, you should have an XL280 or two laying around, as well as a XL295 and a couple XL300s. They're common engines that are GREAT to have a few spares of. Grab one or two of those, rebuild on them, and drive on.
Second, DEFINITELY do the twin mediums over the single medium pulse. Why? Well, changing NOTHING ELSE about the build you posted, you have a HE of over 50% as you built it with the single MPL, and it stays well over 40% (41 or 44, I don't remember) changing that to dual-ML. Over 40% is relatively cool, and that's higher DPS at longer range. Throw in a ML range and ERLL cooldown module, and you're set! (I run mine with THREE MLs, and two ERLLs or LLs.)
Third, I'm not sure that the ERLL is necessary over the LL. They're only reasonable in the arm mounts on the -27, and those are LOW mounts. No good for hill humping AT ALL, and of limited use in corner-peeking. They've got the Cataphract syndrome, where a lot of shots get blocked by speed bumps and anthills. So longer-ranged engagement is maybe not what those mounts are good for. THAT being the case, may as well save some heat and gain some DPS by moving to regular LLs. OR, with a light-enough XL engine, you maybe could even stuff in some LPLs. But even standard LLs will make more sense, as they'll be able to do the same damage, for less heat, more often, at more reasonable engagement ranges for the low-slung arm mounts.
IF you're going to remove anything for that third ML, let it be a single AMS and a half-ton of AMS ammo. You can send the other ton to the leg, as these things don't tend to get legged often. 0.5 tons each for the AMS and the half-ton ammo bin, means 1 ton and 2 slots freed for a 1-ton and 1-slot weapon. WIN. And you've still got a single AMS with a whole ton of ammo (I usually carry only a half-ton for a single AMS). ***EDIT*** LIKE
THIS. ***EDIT***
I <3 CRABS.
Edited by Sister RAbbi, 12 March 2016 - 04:49 PM.