tldr; out of all of them, domination is the least broken. it’s a straight up contest of skill in holding 2 points, minus the map advantages. in order of broken-ness: combat recon, beacon hunt, detonation, capture the beacons, domination.
combat recon - mass inty rush can kill most commanders, especially if you warp in an engineer. pretty pointless mode and can be won in 30-60 secs with organized teams.
beacon hunt - 20 sec spawn hold, plus 30+ sec downtime is just broken… it allows the enemy who defeated you but didn’t take the previous beacon to get 2 free beacon caps. (see post below)
capture the beacons + beacon hunt - ecm metastable and covert camo break these modes by being able to cap beacons. beacon+cover placement favors 1 side over the other in some maps.
detonation - ecm and covert disables still break this game mode often times. can’t count how many times i’ve gotten free bomb plants flying ECM. also, bomb is invisible, so you can hide it…
domination - usually 1 beacon is mostly useless, since the 2 closest/defensible ones are usually taken+held. beacon placement also favors one side over the other in some maps.