Are you super into hair and makeup? I think usually with a vanity you want some lighting coming from the front, so that you don't have shadow on the area you're trying to see. I really just put on lipstick, though, so it would be fine by me. ;-)

The one thing I will say is that the photo may be deceiving...IDK what innovations have been made in recessed lighting, but we have it in several places in our house, and you actually see the bulb when you look up. In the photos it looks just like a beautiful halo of light, but in reality it might not be a look you love. :-) I guess there are ones that have a little screen between the bulb and the ceiling...probably more of a PITA to change the lightbulb but that might not matter so much in a guest bathroom. Just make sure you see the actual fixture before it goes in instead of just specifying recessed lighting.

I expect your guests might appreciate lights that don't cause shadows on their faces. I love recessed lights, but for a vanity, I want lighting coming from the front, even if I am a visitor.

I agree tih redoredone. any kind of lighting coming from above is super unflattering. even if this is just a powder room, your guests are going to hate the way they look when they glance in the mirror.