Taking all the quirk bonus. The ML is just for point blank self defance and close range assist harvesting, take it out for a TAG or more ammo if you want The cool.eff is not realistic, you will most likely not be firing your ML when you can use the PPC and LRM.
Full disclosure: I'm not in love with the Zeus, this variant in particular. I really feel like they phoned it in on the quirks for this chassis in general, but maybe I'm just missing some synergy. Even with quirks, an ER LL is better than a PPC in every way (DPS, DPH, Range, DPT, DPC). The only part of a PPC that is better is DPV (10 v 9). So that's pretty meh-worthy in my book. But, I still took a PPC, because I enjoy them, and it's not a giant 1.25 second tracer pointing to your position. So my fit: 3x LRM 10 + A, 1x PPC, 2x ML, TAG, and BAP, with an XL350 engine. Obviously BAP & AMS are interchangeable. Swapping the PPC for an ER LL means 2 more tons of ammo, or upgrading to MPLs. I dunno. Nothing feels special about this mech I guess. Lobbing LRMs over your shoulder is kind of fun though.