To be honest, the few times that I've shopped in the men's department I have felt more comfortable than I ever have been shopping in the women's department. I always felt like someone was watching me in the women's department because I've always been a pretty masculine guy (I blatantly refused to wear anything girly all my life). I'm not sure what it'll be like when I'm actually in guy-mode (rather than trying to hide that I'm a transguy) but it has never been uncomfortable for me to shop in the guy's section.

Nervous as all hell! And it took me a while before I stopped being so nervous. But I felt better compared to shopping in the women's department. Then, it was miserable.