Gee,
The only time I ever had a guy massage me was when I separated my shoulder and the physiotherapist administered "massotherapy" to aid in the healing. It was absolutely incredible "in that professional context" and I wouldn't hesitate to have another male massage my shoulder again.
When it comes to a full body massage however, right or wrong, I see it very differently. I go for a full body massage primarily to fall into deep relaxation and secondly to help some aching muscles after a particularly grueling workout or a weekend of deck building, etc. Personally, I would find it hard to relax if a guy were massaging my hamstrings and glutes. I know the intention would be purely professional and the guy would probably be unaware of any unease that I would be going through.
In my mind, intimate, relaxing and soothing touch is most natural between members of the opposite sex. Even more simply put, touching of the intimate areas even for medical reasons would seem less "weird" (to me) by a female. When I get to the age where a regular prostate check is part of the visit, I would prefer that it is done by a woman. On teh other hand, I do know some guys who feel the exact opposite...they want their "acorn-sized problem area" looked after by a fellow male.
All I know is that for me, I'd rather have a cute female getting the knots out of my lower back, glutes, hamstrings and quads more than a guy. I know it shouldn't matter...the best massage is the one that leaves you feeling the best afterwards but, unfortunately, gender does enter the equation for me.
Good luck with your future practice!