Energy weapons are pretty decent overall. That said you absolutely need crafting to get the most out of them.
Plasma pistols play very similarly to sniper rifles in that you can stack their critical damage to ridiculously high numbers with an amplifier, practical physicist and critical power. It's entirely possible to one-shot the final boss with a crit execute, or 2-shot him with 2 standard crits.
Electroshock pistols have decent AoE damage and stun to the primary target on top of that. Their critical damage can reach very high numbers as well. That said they work much better as a secondary weapon than a primary.
Sadly laser pistols are unimpressive. They are very comparable to 9mm Neo Luger pistols but simply worse, yes they can stack critical damage high, but plasma pistols are much better for that.
The real kicker is the feat limitation. Steadfast Aim seems tailor made for Plasma pistols, but it's quite costly to put 6 strength into a pistol build, and you have to make some hard choices if you want this feat, such as forgoing Practical Physicist or Stealth+Interloper, and losing out on Perception points to get your AP cost low enough to fire more than once per turn. Steadfast Aim is the only reason to tolerate the very high AP cost of Plasma; other than that, with it's secondary damage types it seems pretty "meh".
Steadfast Aim is a strange feat. I feel it is intended to be used for high AP pistols (be it .44 hammerer or plasma) but only together with riot gear with a shield. Since riot gear with shield requires 4-6 STR to be used without penalties, the synergy is pretty obvious.
The problem is riot gear is lackluster compared to other options. I can't think of any situation where I wouldn't rather be using infused pig leather armor that is actually a better anti-melee armor than riot gear is, except maybe if I wanted bio protection from the vest, but that's stretching it.
That said 3 point into STR is not that much of a big deal for plasma builds. You only need 11 DEX to shoot twice with point shot, or 13 DEX if you want to shoot 3 times with point shot and adrenaline, that's not too bad. You would need 17 DEX to reduce their AP cost to 25 and shoot twice with regular attacks. While possible, it's hardly worth it. Steadfast Aim is not an absolute must for plasma anyways.
Not getting Interloper is hardly a big deal. The feat is little more than a convenience. Practical Physicist is almost mandatory for plasma though.