Did you use most of your weapons and upgrades throughout the match, or did some of them just take up space? I've noticed (as have others) that it's hard to get them all fired off. Personally, I like having lots of options because you never know when that stuff will come in handy. Saturday was the second time this month that I was dealt a Munitions Failure card and had to discard a secondary weapon. Fortunately, both times I had Proton Torpedoes so I didn't have to discard my ion cannon (the first time this was with Horton, and Saturday it was with Krassis). That worked out quite nicely.
I've played with the Firespray a lot since the Kessel Run. I'll break down my observations by weapon.
The HLC is glorious. Out of a couple dozen games or so, I tend fire it off twice or more in a single match. The only instances where I've fired it fewer than twice have been when my opponent's force was decimated and hunted down quickly. The HLC is so good in fact, that often when given the option of target lock + missile in a given turn, I usually choose to fire the HLC + a re-roll instead.
The Assault Missile has gone unfired in several matches, and in a couple of the matches that it was fired off early, it dealt no damage. Usually I fire it off when I can hit 3-4 ships with it to maximize its potential, but I've become less precious with it, being content to deal damage to 2-3 ships instead. In games that I didn't fire it off, its mere existence has been threatening enough to tempt my opponent to spread out their forces. I think the psychology of the missile can prove more effective than actually hitting several ships at once; divide and conquer is a super effective strategy.
I have only fired off the Proton Torpedoes twice ever, and even then, only to moderate effect. I have sacrificed it to the Munitions Failure once as well, sparing my precious HLC. I'm on the fence about keeping them, 4 points is just on the cusp of too much to pay for an upgrade that's usually just a back-up.
I've played with the Proximity Mine with mixed results, having out right destroyed ships as well as doing no damage at all. I prefer the Seismic Charges because they are guaranteed damage and tend to do more total damage than the mines. They've gone unused a few times, but more often than not, I wish I had them in builds where I skipped them.
I usually don't bother with a co-pilot. I've gotten limited use out of the ones I've used, but it seldom feels worth the points. That said, if you have the points to spare it can totally make the difference between getting shot by an extra opposing ship or not; and that much luck mitigation can often decide the game.