I would choose this design as the guest bathroom because when I looked at the picture, I got a welcoming vibe and I love when there is a couch in the bathroom too. I might change out the tube for a shower though because they are more convenient.
Claire - To give you a sense of how original lighting would make the space feel. They have light all around basin unit (above, behind and below) as well as lighting that goes around the bath - in this case just above and along but imagine that same intensity around the perimeter of the ceiling above the shower and bath area. If you use the correct warm light (nothing too white or harsh) and not too powerful the effect is stunning!