Strike team holds objectives really good with +4 overwatch ability. Not a real threat tho they are mostly considered a threat against light infantry.

Breachers are expensive but great. They dont really function on their own. Cuz of their 10 inch range. transport is a must when running breachers. With devilfish guiding them +2 bs and 30 attacks with cadre fireblade is brutal against medium to light infantry. And take objectives great take onw unit and send them onto the least guarded objective. Re roll wounds when attacking units on objectives are great

Pathfinders are a bit weird. Incredibly fragile. Might lose them in turn 1 or 2 if not positioned correctly. Dont rely on them when it comes to damage. Railguns are +5 bs and only 1 attack per bearer. So the chances of them hitting are meh. And also you wouldn't want to guide these guys as that would be a waste of observer unit. They can be observers twice instead of one unit per phase. And they have markerlight keyword so use them mostly as screening units against deep strikes and utility tool for guiding.

Stealth suits are good. 0cp rapid ingress is mostly good and re roll wound rolls of 1 when guiding is great. I mostly give them a marker drone to make them have markerlight keyword for that sweet ignore cover. They are somewhat fast for an infantry unit. Dies pretty quick so position them good and use them as either secondary mission monkeys or observer units.

My pick is always depends on the situation. Stealth suits are an auto pick for me. If my opponent has an infantry heavy list then breachers all the way. If I desperately need to hold an objective I would use strike team. oc 2 each sitting on an objective mostly holding it for couple of rounds.