Hardware-wise, IMHO the NCR soldiers are more like a cheap postnuclear 'discount version'. Pre-war US infantry soldiers had a wide variety of firearms, heavy weapons up to and including tactical nuclear catapults, lasers and plasma weapons in their arsenal, and practically all pre-war frontline combat troops had power armors - Everyone else in the military pre-war had combat armors as standard issue, as well as mechanized transport and robot support.
In contrast, the NCR grunt gets a semi-auto rifle, some ammo and what amounts to a uniform with some mildly protective bits about equal to a WW2 era flak jacket perhaps. Transport is mostly via boots etc.
Elite NCR soldiers we see in game are the NCR Rangers, elite of whom wear a variant of 'Riot Gear' type armor which is actually better than the basic versions of Combat Armor. Basic NCR Ranger Patrol armor (worn by most rangers in the field) is about equivalent to a combat armor in protective values.. In short, NCR Rangers are quite a bit closer to pre-war military hardware standards, but still fall short in several of the equipment categories involved.
However, the most notable thing about the NCR Military in the post-nuclear setting is that it is one of the very few well organized large armies in existence with proper applications of modern military strategy, logistics and command structures. This is a very rare thing indeed in the world of Fallout after the bombs.
Yeah true, Ranger armor is about as efficient as pre war basic combat armor (but hand made in NCR) where Black armor is best non power armor NCR managed to salvage.
However despite having the best logistics and Command structure NCR military still does some rather stupid things, for one they act recklessly with their manpower leading multiple simultaneous campaigns, Expansion in Baha, war against the Legion and ongoing conflict with BoS, they have a sort of arrogance reminiscent of pre war US, but without a protective layer of ocean between themselves and their enemy, so their hubris can cost them dearly in case something goes wrong. Unlike actual US that can always count on it´s homeland being secure against any invasion owing to the fact that any invasion would have to establish a beachhead and hold it with ridiculously stretched supply lines NCR shares a land border with a number of other factions, and should they overextend themselves any one of this factions can decide they are ripe for the picking wit catastrophic consequences for the NCR.