It is the service aspect that make the big difference for me as well. I really dislike having to wait for things and even small mistakes can ruin (parts of) my holiday. The personnel to guest ratio is important, but most of all it is the quality of the personnel that makes a stay in a hotel really great and memorable. If they can read my mind so that I do not have to ask for things, remember my preferences, surprise me with proposals that I did not yet consider, without making it sound like they try to sell me something extra, I truly enjoy myself. Also facilities, design and room is important, of course, but it is easyer for a non-luxury hotel to copy this than it is to be able to deliver great service, not saying I do not want this as well. I do not have a specific preference in terms of which style the hotel should have, I can like the grand old dames equally well as a brand new modern hotel. However, the quality of the bed and the aircondition is something I care much about - in addition to the thoughtfulness of the details, which could be small things like how to switch light on/off while in bed, space and layout of wardrobe, mirrors, where and how I can put my creams and bottles etc. etc. Again there is not one best solution, but when I stay in a room where it is "right" I just know.