I love waxing and I think under-arm (arm pits ;)) are a pretty rewarding wax. I HATTTEEEE shaving my arm pits as do most woman, am I right? It's annoying and pretty darn gross, why not get rid of it for weeks with a quick wax?
Keep in mind when doing this that the top section with grow one way and the bottom grows another this means that you will most likely need to do it in opposite directions to get all hairs with two separate strips, I know it's a bummer. Also remember that if there is any left over to then use hard wax or tweezing so you aren't going over the same area where soft wax was just placed. Now go enjoy those silky smooth pits ;)