Currently Guns have no downsides and it's not likely to change either.
And EW is too hand in hand with Guns to have their true downsides either.
So honestly?
New Vegas' combat skills all svck (IMO I guess) and are not properly balanced (IMO?) and won't change until maybe the next game.
How I interpret Guns and EW:
Guns should be the all around great availability class.
They have tons of weapons available for them right at the start and have tons of ammo as well.
All great right?
Yeah?
Well they don't match up to EW or Explosives in terms of damage.
Guns real Pro is it's availability.
It's Con is that once you get near the end level then your weapons that "do" good damage will require special rare AP rounds which CANNOT be crafted. So you've basically made the choice to have an easy ride all the way up to mid-high level, and now at very high level you'll suffer the consequence for it.
Now don't get me wrong, the end game isn't "impossible" for a Guns user.
But it's harder.
A lot harder.
EW is different.
Pro's
* Great damage. (A lot better than guns)
* Great critical damage. (Better than guns)
* Little variety in ammo.
* Great critical hit % (Better than guns)
* Very little spread with laser weapons. (All except gatling laser and RCW should have 0.0 spread, and even GL and RCW should be incredibly accurate)
Con's
* Scarcity of weapons and ammo.
* Expensive repairs.
* Expensive weapons.
* Expensive ammo.
* Horrible availability.
* Ammo weigh... A LOT!
So, EW is meant to be the top dog when it comes to direct damage. (Not AOE damage)
So what is it's con that is suppose to even it out?
Well. Ammo is [censored] expensive!
And it's rare as well. (Not like Alien Power Cells rare but yknow, rare...)
So finding 30 MFC would be like finding 2000 caps within the first 10 hours of the game.
It's power in direct damage is balanced by it's horrible availability and expensive items.
So missing 5 shots with a Multiplas Rifle would earn the TV a remote through it's screen.
Anyway, that's how I interpret them.
And no, this cannot be done in Vegas.
What's done is done.
All I can hope for it that by FO4 it's more along these lines.
Cause I don't believe that Guns and EW should be "equals".
On one side you have a bullet, on the other you have a freakin' laser beam!
They're not the same and should not follow the same tier system IMO.