centreset usually looks cheaper in my opinion (which of course is worth very little).

I don't know about asthetics, I think each one can look really nice if used in the proper environment. The higher end bathrooms usually (and I usually because I inspect homes for a living and see centerset used in higherend bathrooms sometimes too) have wide set. We have centerset in our .5 bath so I can say from personal experience that their harder to keep clean because the spacing in between the handles and spout is so small. We have wide set in our master bath and their ok to use and easy to clean, but my favorite is single lever. Simple and classic. I sometimes regret not getting a single lever for our master bath, but live and learn.

Widespread are easier to keep clean than centerset but both can look nice.

Widespread, 100% of the time (imo) unless it's a tiny powder room.

our contractor said that wide spread is rule of thumb for granite counter tops/and I guess single level would work as well but the centerset holes are more difficult to cut I guess---
what about the mini-spread sets--would they would ok with granite