This is by far the most powerful nova build I have used or seen. Why no one uses it, I have no idea, but credit for this goes to my friend Razor Drive who doesn't use the forums here. This build is similar to the FireEmber, but it sacrifices range for actual brawling potential. Your goal is to stay behind cover and avoid the early sniping portion of a match, and then when a real skirmish starts you can just walk in and rip off every damaged component on your enemies. The main point is to keep the element of surprise. You can generally sneak in to any brawl or skirmish and core or disarm several enemies before they see the threat. That gives you time to cool off and use your MGs to finish them. The Nova is not your usual brawler, it's breaking traditional play as most of the clan mechs are designed to do. You don't need to outlast, you need to out damage, and take away their weapons before they get to hurt you.
It's not often that you need more than 10 seconds with 20 DPS, because in 10 seconds you've dealt 200 damage and in that small of a window you've won the brawl, whereas the higher sustained takes around 15, which gives the enemy 5 more seconds of shooting you. The point of the MGs as I see it is to allow you to deal a decent amount of damage while you cool down after you've cored/disarmed your foe. I don't think the Nova can really survive long enough to make use that higher sustained DPS. The main advantage the nova has over other medium brawlers is it's ability to quickly destroy components and leave your foe mostly disarmed, rather than using a shield torso/arm to tank damage while you try and break them first.