I'm generally in favor of the umbrella-ness of the term transgender but the limitations can be quite clear...
I won't tell you that you are a transgendered individual. However, I will suggest that your behavior is transgendered. As you are one who identifies as 100% male, you are hardly transgendered in a classical sense. Yet as a male who likes to dress up as a female, that is a behavior which is seems to fall under transgender as a description.
I think the umbrella term is easier to get your head around when such a distinction is made.
Especially because the Muggles who know what the "T" is in LGBT rarely have enough experience to understand the differences in those of us beneath that term. One may see Linda who I reference above (I hope you don't mind being used in this example), or myself, or a fully transitioned woman who is still recognized as being trans-something and we are likely to be lumped into a single descriptive category based on that person's experience. Linda might be put off if she is perceived as being transsexual while the transitioned woman may be offended if she is perceived as being a CD. Yet somehow it seems that the rather benign term of transgender could be the least offensive description for use by the uninitiated, even if it proves to be a bit broad or somewhat inaccurate.