I sincerely love my 3xAC2 MAD-3R, so I figured I'd try to replicate an upgraded version using the inherent advantages to tonnage, slots and XL engines with Clan Tech. This is what I've ended up with - Again, using Fire Control for the AC's since I hate jams more than Locusts. Interesting that AC cool down doesn't happen until the last shell has left the barrel, so my previous calculation of 1.66/3 actually ends up at 580ms instead of the 554ms it works out to. Haven't tested it I incur ghost heat if I equip a cooldown5 module and drop the timing to 495ms. *EDIT* Yeah, screw fire control for uAC5's, it's too slow. Just shoot them together, works better.
I got a very similar build to your, but with a smaller engine and more heatsinks Was going to make a topic about it but you beat me too it These builds wreak hard. But can get you cored very easily and fast, if you get to into the zone and zone out situational awareness.
They do a lot of damage. Being able to get a nice, consistent double tap with all 3 does great things. But yes, I'm finding that having to face lots without twist is kind of an Achilles heel for this mech. And side torsos! Jeez do those get cored out fast.
I've been using something along these lines of late, having finally refit my MAD-IIC-A from a long-mothballed ill-advised dual gauss configuration. I'm rolling with a bigger engine, though. Heat seems totally manageable, and I'm having lots of fun with it.