To start im going to be talking about balance of the weapons and classes. I would like to stress the fact the game and guns Feel solid and Personally and statistically have not found any issues of any weapons dominating over another. In short you may use anything you like and do as well as you want and be fine. Again the balance of the weapons themselves is fine TTK is fine shots to kill is fine ranges are mostly fine etc this is about Most things not having a use in the current game.
Im gonna elaborate and put down some ground work some people may not agree with these and have argue points which go ahead and argue but im going to try my best to post statistical and factual information based on the current community, gameplay and what has been generally said. The AK-74 currently is the best automatic especially with mods. The DMRs provide no true and real advantage over an automatic (I will explain soon), Sniper rifles are near useless and niche and do not provide much. SMGs depending on the gun are outclassed completely or just in a weird spot. Most of the balance between things are actually fine.