I agree with everyting, except that going-up is less comfortable. I find it very comfortable.
It's true that in the up position the erection is less noticable, as it is held against the abdomen. From the side-view there may be some additional bulge, but it's not that bad. Anyways, almost everybody knows what's there and how it works, so why worry?
DancingDoc wrote some stuff about this on www.danceart.com on the Men in Dance and Guys Club boards. The erection is a natural response and might not be a sexual response, just normal physiology and a response to circulate more blood.
I don't think that pointing the penis down-ward stops erections, It never has for me! When I'm packed down-wards, the erections can push outward even farther, standing out like when I wear boxers.
Keep dancing! balletboy[/i]