I have been recently bumped up acquisition of Team-Up cards and am feeling a little guilty if they bring too much to a game at the low cost of just building a (sometimes) narrow theme team. Yes, some of them have very low effectiveness (HoX020.04 Marvel Girl: boost when attacking Mind Controllers) but others I think are quite good. Effectiveness aside, they are essentially a revamp of ATAs but ATAs had a small point cost to them that multiplied with larger teams.
As a player who loves theme teams and comic-accurate teams, the Team-Up cards are right up my alley but I feel like I am bringing in extra team value at no cost. Sideline Active mechanic similar but I haven't thought as much about them.
How do you feel about Team-Up cards?