When I see Proton Rockets in an enemy list, I take them out ASAP. I've never seen one fired at anyone.
Precisely why I love a 20 point Prototype with Prockets. They are scary enough that they may take the early heat away from the other 80 points of your list. I still surprise a lot of people with a Procket though, they are great for 1 shotting Zs and Ties.
I wouldn't run them in abundance, but one to deliver nice burst damage is a big help.
Exactly. I like to put them on Tycho along with Push the Limit, Experimental Interface and Expert Handling or Daredevil. That puts him at 37 or 38 points, which means that most opponents will do everything in their power to try to run him down. I usually just have him spend the entire game running away while the rest of my list does the actual shooting. I've had games where the other player literally never landed a shot. If he fires them, it's basically a dead ship on the enemy side, but in my experience the threat is worth way more.