Hmm I've been mostly playing 451v this season and im 1st in League , Cup Finals and semis in Super League .. It seems pretty good against most formations so far.. I've NEVER lost against the standart 442.. I only had troubles in the beginning of the season against 4-2mc-3w-1 but I found out that the tactics I used were not good (played attacking down both flanks,offside on counter on; and then switched to normal mixed mixed on HIGH, off) and lost once against 4-4-1-1 which was a bit of a troll game ..
And considering 11 out of 13 teams in the league are full 6* teams and the super league and CUP opponents were fairly even to mine I cant really say bad things for this formation.. ofcourse against tactics like narrow diamond which i know perfect counters that are not 451v i used those instead..