Transamerica, should they have cast a real MtF instead of Felicity Huffman?

I haven't seen this movie yet and have wanted to, but have yet to because I was pissed that they didn't cast a real ed person (or like in Soldier's Girl, they cast Lee Pace to play Cally, using make up and other effects)....Did anyone else think this prior to or even after seeing the movie? How did FH's performance measure up? How was the movie in general??