If the hotel entrance is on 28th, is it easier to come from 6th or 7th ave?

Come from 7th

Agreed on 7th being best by car. Also, walking to/from the hotel in mornings by way of 7th gives you the full experience of the flower district, as the sidewalks are filled with plants and flowers for sale.

If you are driving, it is easier to come from 7th as 28th Street is one way, west to east