I love my HBK-4P(S), and mastered it with 7 ML in the head and hunch and an ERML in one arm for UAV's. Then, I saw Bearclaw running something like this (below) and figured it was silly not taking advantage of the Medium Laser HSL +1 quirk. Then I tried it. With a fully skilled hunchback (all four laser duration nodes) combined with the 10% laser duration quirk and the hard points, this thing is freaking amazing. I was running around killing enemies left and right, being careful and working corners. It was shocking. I even got two teamkills in two games from teammates running by in front of me as I was firing my super-convergence super-fast pulses into a dying enemy. It's powerful. I like standards in this build, because the heat is much more manageable if you lose an ST and the drop in kph is minimal. I keep the hunch in weapon group 2 and the head in weapon group 1, and I stagger when it's easy, but the ghost heat when I'm in a hurry isn't a big deal.
Ohhhh.... I didn’t realize that the HSL+2 quirk applies to MPLs - I thought it was for MLs only. I’ll have to try this tonight. I don’t see much point in running STD engine. If you lose the left torso you lose 4 DHS so you will be very limited by heat and very likely shut down from the DHS loss heat spike - and die. So you may as well run LFE275 maxed engine, or XL275 and go to 8 MPLs to make full use of the HSL+2 quirk - the latter will be hot inspite of the extra DHS and you will be popping coolshots like they are valium pills - but when going glass cannon, you have to go all the way! LFE275 with 7 MPLs and better cooling: XL275 with 8 MPLs:
According to Mech DB it does apply only to standard and ER medium lasers, also the following statement confirms what I was thinking... 7xMPL does actually trigger ghost heat like before patch, but is bareable due to DHS buff and DHS boating.
Seriously, those 7MPL's with full laser duration nodes and the laser duration quirk ROCKS. It made me go through all of my mechs to see what other mechs have 6+ energy hard points along with 10% laser duration reduction so that I can do the same. I set up my Blackjack 1DC with 6MPL's and 2LMG's with the intention of hitting those nodes, as well as my Marauder II with the energy hard points. There might have been more.