Probably not, since X-COM armor ratings are damage
reduction. Along with highly random damage rolls (0-200% IIRC), but that still means the extra ROF from laser pistols isn't worth their lower damage. Too much of it gets ignored entirely.
A similar case is easy to make against laser rifles, but using heavy plasma for everything gets boooring. Even if it is just better, I was able to beat the game with a focus on laser rifles. See, the trick is to scout with a disposeable rookie - then have all the actual soldiers, pretty much anywhere else on the map, just let loose. Original X-COM doesn't have distance penalties, see, only a mechanic for "misses" to hit despite going off-target. Which matters at close range, but you can still auto-fire across a map with impunity.
Why's that good for laser rifles? They're accurate and you can literally just autofire them forever, of course! Law of averages (kidding) means that with enough "snipers", some are going to land, and some of those will overcome the armor. With heavy plasma you can burn through clips... technically. Once all the aliens carry it, that's not usually a problem, but it at least calls for a *little* restraint.
Also one of the worst late-game terror enemies is vulnerable to lasers. Bonus!
Laser pistols are safe to stick on rookies though, good for training their reactions and accuracy if they happen to survive.
As for personal armor: For me, it is literally for color-coding the soldiers I care about from those I don't. There's statistically a difference, but heavy plasma barely cares about full power armor much less alloy.
Edit: And yeah X-COM's line-of-fire rules are kinda BS. OpenXCOM dutifully recreated them as a matter of design philosophy.
The colorful chart halfway down
this page, showing unintuitive blind spots, probably applies to OpenXCOM as well.
Not to mention the "Line of sight comes from eye level, line of fire comes from shoulder level", which is to blame for a lot of window situations. Remarkable attention to detail/"realism" which basically just means frustration in actual gameplay.