i absolutely love the gunzerker i havnt played as the commando but i did play as the assassin and if you enjoy getting into the fray and just absolutely mowing bad guys down id recommend the gunzerker 100&
I have an Axton at I think 36-37 right now and a Salv at 5, I do like both of them feel much more gun centric (absolutely love Axton's metal storm skill, I like to think of that as his action skill more than the turret)
But for some reason I personally feel awkward using both triggers to shoot while gunzerking and using salvador, but don't feel encumbered in other games while duel wielding.....it's weird haha So I prefer Axton for that reason.
GT: Social Sin Fanboys = The bane of any intelligent individual
While both have the same base cooldowns(42s) and durations(20s), everything Salvy does is player based, meaning, zerking allows the players to go H.A.M. and kill everything he/she selects to be dog food. While Axtons turret is picky and can miss a target all together. Too much of Axton's abilities rely on staying back and dropping a turret, which would be awesome if it didn't suck for about 30 levels. Too much time is spent waiting to get a cooldown reducer and or relic and class mod to lower said cd time.
Of course it all comes down to how you like playing. Salvy is all about running into the fray and running through magazines(which get refilled if specced correctly) and maxing out his total dmg output. While Axton is as mentioned before, all about the cover, he's the epitome of a "team player". While soloing can be fun with Axton, its only in the later levels.
Final note; Gaige puts Axton to shame when it comes to a "pet" class. Not only is Deathtrap more aggressive(he can chase down targets) his move list is ridiculous.
"Heaven cannot brook two suns, nor earth two masters."
i have both characters at level 25 currently, and from what i have seen, salvador is more fun to play but axton is more practical. the gunzerking alone can mow down anyone (especially if one of the guns is slag and the other a second elemental). problem with that is, if you get downed while gunzerking, you automatically lost your second gun. axton, on the other hand, if he gets downed while his turret is still out, it stays out and if it kills something, that counts as your kill revive. also, if you compare each of their tier 3 and tier 6 skills, axton has a lot more to contribute as a team player (can add rockets, phalanx shield, second slag gun, second turret in general, or a nuclear bomb turret). my advice: if you play solo, go with salvador. if you play with at least one other person, go with axton. but if you're going to go with pure fun, salvador is the way to go