I haven't played it yet today but the beta was a lot of fun (and more or less the final game anyway) and it is very fun and while the Americans have a huge advantage in weapons they don't always win or at least pay a very heavy price (although the Japanese have to work together). The only really weapon I'd say is OP is the flamethrower, its way too easy to use and on some maps and capture points it makes extremely short work of the Japanese defenders in a building IF it makes it in range (its pretty much #1 priority to shoot).
You can still play RS, but only as riflemen, along with regular RO2: HoS if you don't own it yet. I think the 40% discount for those who already own RO2 is over now though.