The Dahmer to The Fenrir, using this Dart Tagging beast as an add-on to already awesome blasters seems to be the way to go with it. The internal layout and design of the Swarmfire lends itself well to being freed from it's plastic prison and being hooked up to something else to make for an awesome combo! However, I haven't really seen this blaster optimized for use on it's own. It always seems to be an accessory to something else. I've personally used the Swarmfire in games before with great results and, for whatever reason, I didn't continue to pursue that.
There are obvious mods for performance that can wring better results out of this blaster. Remove all the dart pegs, Up the power, and BOOM. Instant success! But maybe there were other things we could do with the Swarmfire to really make it a fantastic standalone blaster. Give it some optics to help with aiming (there's really no way to sight this), lengthen the stock a bit, add some external ammo storage, maybe something I haven't thought of yet.