Agreed with above poster. I have very little downtime using Mako and while yes, most of my attacks are missile based, it's still a blast (no pun intended) to play.

Yeah, but Power Shot doesn't add the debuff to reduce armor

Level 22 Merc, and I think I've found a good mix that helps my heat ratio. I open with Explosive Dart, followed by 5x Tracer Missile (this will go down to 3x once I get it specc'd), I then Rail shot and Unload. At this point it becomes a pretty easy process that I follow in this order: 1.) Is Heat Trace about to fall off the target? Then cast Tracer Missile Always have five stacks of Heat Trace 2.) Is Rail Shot available? Then cast Rail Shot 3.) Is Unload available? Then cast Unload 4.) Is Explosive Dart available? Then cast Explosive Dart 5.) If I've reached this far, it's filler time. I generally use Rapid Shot as my filler to help keep my heat cost down. This works wonders for me and I can go almost an entire boss fight without needing to vent.