Well, it's always been a private concern of mine that the tech wasn't fully explained for energy weapons, but, it is science fiction after all. You either accept the handwave, or you do without.
It depends if I am writing a story or running a game. I tend to run more of a simulation than a game, where I like to have hard explanations for what happens. Projectile weapons I know a lot about and have large amounts of hard data on. So, go with the equivalent of Piper's Space Viking for hand weaponry. If I were writing something on the order of Andre Norton sci-fi, I would likely go with some energy weapons. That fits the milieu.
I am curious though, no starship combat and no energy weapons. I'm curious what your gaming sessions were like.
The guys liked a combination of Belt Strike with the strike system in JTAS 3 for asteroid mining. That works pretty well, and they came so close to that big strike that they kept trying. Never rolled any attempted claim-jumping, and nobody died, although that was close a couple of times.
Then they went trading along the Spinward Main, and I was trying to get them to either Research Station Gamma or Twilight's Peak, and in that they would have some energy weapons, maybe. I went with the rule for their Free Trader that the route was sufficiently well patrolled to keep piracy to a minimum, and mainly going after high value cargoes. So never had any space shoot-outs, where I would have gone with the rules, but then, I was using the GDW adventures. They never caught on to either adventure, but did have a lot of fun making and then loosing money. They did do some hunting as well, but never really got into any shoot outs on the ground. They were not that type of guys.
After working with that, I have since been working up my own Traveller universe, where the rules covering man-portable energy weapons hold, while the space combat rules I am working up make it short and deadly, with energy weapons used mainly in self-defense against missile fire. Again, more like Piper than anything else. I figure this is a role-playing game, if someone wants to fight large-scale space battles, I will break out my copy of Imperium and have at it.
Now, if I had a group that really, really wanted energy weapons, I would have to do some thinking.