currently, if you play a theme team and your opponent does not, you have the potential to gain the upper hand.
but what if your opponent plays a theme team as well? i think it would be helpful to approach it in the following way:
your opponent will either
1 - play no BFC, which evens the hand (sometimes)
2 - play ordinary day, which is a confusing nerf of a tactic, but one we can disregard as you'll see below.
3 - play a "positive" BFC which evens the hand (sometimes)
4 - play a "negative" BFC with the intention of ignoring it
Check out this team:
V Multiple Man + Contingency Plan 56
JL Plastic Man 55
JL Batman 75
R Question 40
U Spider-Woman 67
Total 293 (7 points for feats of your choice)
It's a nice Detective theme team. Three (3!) Outwitters, with Batman and Spider-Woman fronting the offense, backed up solidly with Contingency Plan, and Plastic Man's harasser's dream dial.
Now here's the kicker - the BFC to put into play is Inertial Interference Field. Batman doesn't need it, Plastic Man doesn't need it, the other figs aren't bothered by it at all.
So if your opponent
1 - Plays no BFC and yours is played, they'll ignore yours, it won't effect you either way.
2 - Plays Ordinary Day and yours is played, they'll cancel yours, it won't effect you either way
3 - Plays a "positive" BFC and yours is played, they'll ignore yours, while you gain a bonus (sometimes)
4 - Plays a "negative" BFC and yours is played, your opponent will have to choose which negative condition they wan't to avoid the most. Since Inertial Interference Field doesn't bother your team anyway, you can just ignore you opponent's BFC.
In short, I think it's a good idea to build a team that isn't bothered by the BFC/s you'll play AT ALL, rather than building a theme team with a nerfing BFC that you intend to ignore. Try to go into the game always ready to ignore your opponent's BFC and give them something to think about.
Anyway, I hope this made sense or was helpful to some people.