the idea is neat. a faster moving heavy suit with two light slots instead of a heavy and sidearm

the execution doesn't make much sense. here are the downsides to the above listed upsides
*it's horribly expensive, 20% price increase on basic suits (aren't specializations supposed to be cheaper?)
*the base armor and shield HP are almost halved (250 from 400)
*the slot layout is pretty awful. proto only has two highs and one low if i remember correctly
*the pg/cpu for fitting is less than the basic

so i ask, does anyone use these suits?

I use the Laser Rifle and Assault Scrambler Rifle and honestly I chose that simply because I'm really big in the Amarr but after playing several matches I think people should really give it a try. The Laser Rifle is fine in my opinion, the iron sights don't bother me whatsoever (and yes, I was there during Chromosome). I am able to run around with the assault scrambler rifle and take out anyone who gets within a decent distance while being able to quickly switch weapons to melt the face off anyone just outside of my range.

sounds kind of over-specialized, mostly because the assault scram does ****-all to armor so it doesn't make a very good cqc panic weapon

*it's horribly expensive, 20% price increase on basic suits (aren't specializations supposed to be cheaper?)

I saw one yesterday.
He was using a sniper rifle in an improper fashion.
I killed him with a militia AR.

I've been having tons of fun with trololo-Halo-style shotty/snipes and shotty/TAC builds. Shotty/LR works too. Basically, bait them in with your obviously mid to long range limited gun, then sit behind a corner as everyone and their mother comes for your big red heavy suit, which, surprise, is holding a shotgun!
Proto suit isn't nearly worth it though, IMO the commando is a for fun only suit, meant to be run at STD for people who want to troll DS3 users with superior KB/M gun game and the perfect weapon for both short and mid (or mid and long) ranges.
The main factor (in my brief play experience) that limits the commando is its abysmal shield recharge rate. 10/second is ridiculously bad. I was hoping for a suit the laid heavy penalties on me but rewarded excellent gun game- instead, any clash with an AR has me retreating for 30 seconds while my shields recover. Terrible shield recharge rate, with no slots for armor reppers or recharge boosting, leaves the commando (arguably even at proto level) more fragile (in terms of the kill->recover bounce cycle) than a starter C-1 assault fit.
To fellow trollmandos: always run with a compact nanohive, 50hp/s self rep once per clone for minimal pg/cpu and ~900ISK really helps.

TL;DR: it's a terrible suit that's fun to troll with. Definitely deserves to be in the game, it's not teh hardcorez CalLogi competitive but as a casual player I'm loving it.

The following isn't intended to be offensive, but . . . . you're playing it wrong.

This is a heavy suit. You don't move as far as medium suits and you have the largest hitbox. You shouldn't be baiting people into 1v1 close combat with you. You should be rolling with teammates and sort of be the suppressing fire while not making yourself the primary target.

And ok, who am I to tell you how to play a game, but you said it yourself that the 10/second is ridiculous. Perhaps you should of drawn the conclusion that this suit is not meant for going off and doing your own thing rambo style but rather being a versatile asset to a squad.