Been playing with this since the stalker released. I'm having quite a bit of fun with it, the damage output is through the roof. The high placement of the four energy hardpoints is really handy, and the artemis keeps the SRM's in a fairly tight spread. The two wasted AMS hardpoints are nagging at me, so I'll likely revise the build once I've played some more with it. I've got the lasers chainfiring on LMB, the lasers alphaing on RMB and the SRMs set to group three - bound to the E key in my instance. Need to watch your heat, I have a bad habit of hitting someone with the missiles and then alphastriking the lasers and shutting myself down. If you're careful about chaining them, you can really put out some solid damage.
I'm sorry, but I hate the idea of an XL engine in a Stalker. I've shot so many in the side, only to watch them explode. A good concept, but poorly done. 1-5 BTW, you say 2LL and 4SRM6, but your loadout has 4LL. Here is your build as stated in the title.
Honestly, I don't know why people hate stalkers with XL engines so much. Back when I played my ERPPC/LRM stalker with XL, I kicked ass in every single game I played with it (averaged 700-is damage per game); the XL engine was never this overwhelming problem people seem to think it is. As for scoring, I gave you five stars because I wanted to give you 4 stars, but Vergere's 1-star score fucked it up, so giving you a 5-star score made it average out to 3 stars, which is one star away from the score I think this build deserves. For specifics, aside from the heat efficiency, which I usually prefer to be a minimum of mid-30s percent, it looks very good to me. Good sniping with 4 LLas, and the low heat of the SRMs means you won't have to stand there helplessly while you cool down.