Virtually ALL my guy friends are bigger and more manly than I. I would be incredibly surprised to find out that any of them were crossdressers... How would I react? I most certainly would not judge them (duh... how could I?). And I would probably be very supportive. And yes, if someone did come out to me, I would immediately tell them about my own activities.
My opinions of them would generally not change. I can't see how this would damage my relationship with them at all. In fact, I think the opposite would happen. We would become closer because now we are sharing something highly personal with each other.
While this is not at all the same situation, about 10 years ago I was considering moving in with one of my friends that I have known since public school. (Still to this day, the longest running friendship of anyone I know). Believing that this was going to happen, I got him on Yahoo messenger one night and basically outed myself. Mind you, at this point, he had already seen me dressed at a Halloween party a few years prior, so the prospect of me adorning feminine attire was not at all difficult for him to imagine. And in our conversation, I used that experience to warm him up to the news. I dropped the bomb on him, and he totally took it all in. Had nothing negative to say about it. Full acceptance. I was so happy to finally tell somebody (other then my girlfriend) about Tracy.
This relationship has remained strong, to this day. And he usually comes to visit me about once a week. And yes, for almost all of his visits, I am fully dressed. While my girlfriend has no real problem with my activities, she generally doesn't spend time with me when I'm dressed. He's the only person that I can spend any time with being Tracy. So I always look forward to when he comes down. For this reason alone, I can easily call him my best friend.