I've played through the Recon class, and it's exactly what it's named to be, Recon. Not sniper, Recon. Sure you can still snipe, but it's tough, and in CQC maps it's nearly useless outside of spawn beacons when they work. That still hasn't stopped me from using iron sights on my snipers for a challenge in these modes, but the class was designed to spot enemies for the rest of your teammates to kill. They're not god-mode like in other games, but it's rewarding to play for the challenge.
If there's an OP class, it's Engineer for sure. They have an answer for everything. They can hold their own against every other class, and they have ways to counter every armor in the game. Sure you need to rely on med kits and ammo packs, but to me that makes them the premier class in the game. They can single handedly change the game in seconds at times.