The teams are even more different from each other: The US gets helicopters (in some maps), the VC have no vehicles. While guns between teams are mooostly similar, there are some differences (VC get RPGS while the US can get flamethrowers and grenade launchers, for example). AFAIK, teams no longer swap attacker/defender position, US will always attack some maps, and vice versa instead, the game changes your team after each round (attacked as US? Now you defend as VC) so maps are more specifically designed thinking "ah, the defenders will always have these mechanics".
RS2 moves further down the "assymetrical" path. While the US is generally stronger in sheer firepower (every rifleman has semi-auto by default, they get flamethrowers, they get more MGs -even if they're the piece of shit BAR), the Japanese get some more "unique" attack options: They get a class equipped with hand-held artillery (knee mortars), they cat set down booby traps, their officers get Katanas for more efficient melee, they have a mechanic for suicide charges using nades, and they get the dreaded banzai charge (where basically a huge number of them charge you into melee). There's no vehicles, and the teams are very distinct from each other: The basic US riflemen, for example, get the semi-auto Garand, while the Japanese are stuck with bolt action rifles. RS1 moves towards "assymetrical warfare" a bit.
Another difference is that RO2 includes tanks in some maps, usually one per team, though some maps have more, or only a tank for the attackers (there are tank-only maps but they're buggy to the point of being unplayable).
The differences are NOT purely cosmetical (the German MGs, especially the MG42, are considered to be superior to the DPM, while the Soviet T34 tank is generally better than the German Panzer IV, for example), but still, the teams are mostly equivalent and can easily exchange defense/attack positions in a map, and they have the same assist choices (arty, scouts, etc, which the commander can call in). DPM vs M34 for MGs, PPSH vs MP40 for assault, etc). The German and Soviets have different gear, but otherwise their classes are pretty much shared, and each gun has an approximate equivalent in the opposing army (Mosin vs Mauser for the rifleman class, for example. In addition, the Japanese attach bayonets to almost any of their firearms, this is how they get the most dangerous opponents in close combat.There's some other differences besides setting, too (I'll skip RO1 since you're probably not getting that). While the Americans use heavy firearms, the Japanese compensate for the lack of power with their courage and ingenuity, firing from hand mortars, both direct fire and from a closed position, and the cunning Japanese turn grenades into deadly mines. Well, and the most delicious is the network mode with the ability to simultaneously connect 64 players at once! And the most interesting thing in the network mode is the inequality of the enemy's forces, when the weak side has to compensate for the imbalance by all possible methods and tactics of combat. Well, if you are a fan of the Japanese army, then get ready to organize sabotage, mine the area, and, of course, swing your katana to shed the blood of these "Yankees". Rising Storm has not undergone global graphic changes, the quality has remained the same, but the radiant sun pouring over new locations allows you to take a fresh look at the difficulties that have to be overcome: landing on enemy territory, suppressing resistance, destroying defended fortifications using an ordinary machine gun or a real flamethrower.
Take part in bloody battles on the shores of the islands of Iwo Jima and Saipan, spill sweat in skirmishes between the impenetrable jungle. You have to side with the Marines or go the way for the infantryman of the Imperial Japanese Army. Red Orchestra 2 Rising Storm - This is an add-on that will take you from the besieged Stalingrad to the Pacific coast.