Ditto to Rachylou. It's the orientation that ties a woman's worth, or power, to an external stereotypical role or image that makes me uneasy--which is totally different than internally feeling sexy, or womanly, or feminine, or whatever. Dressing to FEEL "sexy", to my mind, is not the same as dressing to LOOK "sexy"--which is also fine, if that's your preference. What makes me uneasy, though, is when women choose to find their power by adopting a sterotypical type of "sexy", or "womanly", or "feminine", dressing that allows them to manipulate others into seeing, and reacting to, them in terms of the stereotype, instead of as an individual.
Regardless of how we feel about the connotations placed on words like "sexy" or "womanly", this discussion shows how powerful these stereotypes are in our minds as well as in the rest of society. To me, the real question is how do we choose to cope with them.