Artemis is really useful in assault lurmboats, as it makes the missiles much easier to fire at relatively short distances with the reduced lock time, so you can still be a great asset at/near the frontline.
Here is another version of that build. I am frequently firing all 4 LRM 15 simultaneously. With some active operation nodes I can actually fire the full volley up to 3 times before overheating. As those volleys do not always hit (e.g. if the target move out of sight), I loaded a lot of ammo on that mech. The benefit is the high damage the target takes from the full 60 missiles, additionally a single AMS won't stop it. I don’t really like to play with TAG therefore I picked 4 lasers, but 3 lasers and a TAG might also work. Laser AMS which provides some cover for you and your mates. I usually try to stay at medium range and focus on enemy assaults.
5/5, I admit it. I'm guilty. I made one of my Madcats into an assault LRM boat. What are you doing with those ERSL's? Those are only going to get you in to trouble, buddy: Pure team LRM support with enough mobility to stick with the firing line. Let the raw missile DPS rain down. They will fight in the shade.