I'm relatively new to RO2 too, about 30hours of gameplay, I never completed single player campaign, just the basic training, then I went directly to the battlefield
I play both Ro2 and Rising Storm, I prefer Ro2, because at Rising Storm Japs uniform is very similar to US, which leads to mistakes and team killing, especially at medium to long range in forest maps where sometimes is almost impossible to distinguish teammates from the enemy. Looking to map may help to see where friendly soldiers are, but opening it on heavy battle is not very recommended.
In Ro2 the URSS and Nazi uniforms are clearly different, so it's where I pass more time playing, even though there are the usual team killing by "deadnades".
The game is very nice, gameplay is enjoyable, cover system is ok, graphics are a bit dated though, sounds are great and of course there are some minor bugs present.
There are more players recently due the giveaway few days ago that the company offered RO2 for free for someone who downloads it in 24H.