Both options are great in setting a mood. I find that pendant lights create a glare if they are hung too low. I personally like the wall sconces because you are most illuminated in the front which is great when applying makeup.

depends on the lights. depends on placement.

post a pic of the vanity area and the lights you like.

(but if you hang a pendant light, with a glass shade, directly in front of a mirror, of course it's going to reflect the light. That's why most pendants around a vanity are off to the sides, or hung high enough above a mirror)