Combined with Romeo's advice not to play USF pro tem, all this fills me with a certain dread.
Any Allied player like to disagree with what those above me have posted? ((politely, of course)
I don't think you'll find a single one.
Playing USF in 1v1, if you won't win by 10th minute, you will loose.
Playing USF 2v2, you're just dragging down soviet and being carried.
Playing double USF in 2v2 lol free win for whoever is the opponent.
The only reason to play USF is if you want to play with stock infantry that actually can fight and don't want to play axis.