The Dragon doesn't operate as a fire support/sniping platform anywhere as well as the Cataphract or Catapult do.
Like the others already mentioned, its main power is in its speed. Its main weaknesses is how huge the CT is as a target.
I'd consider putting the max size XL engine in there as a compulsory requirement to run the Dragon optimally, because in most other situations you should be using the other Heavies instead. Your CT is asking to be shot, so you need to fire sideways/backwards as often as possible. You can spread damage throughout your Mech without losing firepower in ways neither the Cataphract or Catapult can do as effectively. Because of this, putting weapons in the arms also is pretty important. As your CT is huge, don't worry too much about the XL because most of the time you're not getting side-cored, better speed/weaponry will save you far more often. And remember that environmental cover has infinite damage protection, you should constantly be looking for how to shoot people while darting between cover, and you'll live longer that way.
Weight is a severe limitation, so all of the successful Dragon builds I've had so far had energy weapons and a central SRM6 only. Even on the Dragon 5N with 3 ballistics hardpoints, I haven't managed to get any other setup to do as well as a 2 Large Pulse 1 SRM6 setup. On my other 2 Dragons (Flame and... I think the other's a 1C) I use a 4 Medium Pulse and 1 SRM6 setup. With a ping of ~300 no other laser type works as well for me.
With ~300 ping I still can't hit Lights, but I can hit everything else very reliably, very often. Awaiting the anti-lagshield netcode phase III patch - when that one finally comes out, the Dragon can finally hunt Lights as well.
Due to the need to fire with your torso turned very often, utilise cover effectively and position yourself properly, this plays like a cross between a Heavy and a Light (does not benefit from lagshielding like lights do, however). I'd say it's probably one of the hardest Mechs in the entire game to do well in (and something I'll never recommend players try as a first Mech), but a masterful Dragon pilot isn't any less fearsome than a masterful Cataphract pilot. It's just that the learning curve is *very* steep, so the average Dragon pilot will do worse than the average Cataphract pilot.
Edited by Hayashi, 08 February 2013 - 11:08 AM.