Always wondered why he want to QPR. There is something about the whole set up there that doesn't ring true.
Firstly, Macheda isn't as good a player as Fabio in terms of prolonged contribution to first team football. Macheda supposedly put off a lot of clubs wanting him on loan due to attitude problems such as arrogance (that he's a United player) and laziness. At the other end of the spectrum, Fabio turned down Champions' League football as he felt it wouldnt be as beneficial to his career here.
Secondly, Macheda was brought into a team that at the time didn't have Djibril Cisse for competition, and as a result Macheda got quite a bit of football in the first two months or so. Once the relegation dogfight started heating up, Hughes (who didn't even sign Macheda) was forced to call on more experienced heads. Fabio's only competition for the left back spot is Armand Traore, who Fabio easily displaces when fit.
Personally I think QPR is a great place to send him on loan, the amount of experience a player can gain from being in a relegation scrap is huge.