I bought my train room 14 years ago. I needed to move from my apartment with short notice so I didn't have much time to do any remodeling or improvements except to pull up the old, old wall-to-wall carpet. The flooring I could install the fastest was laminate. It is still there throughout the house.
Like me, you don't have that desired basement for your layout. Mine is in the living/dining room of my ranch.
I have area rugs in most rooms. In the train room most of the floor is under the homasote topped layout and covered with boxes. Only the aisles have flooring visible. I don't think that that flooring adds to the sound. The sheetrock walls and ceiling definitely do the most by reflecting what sound there is.
Whatever you do to the floors in the rest of your house, you should do in your train room. Be consistent. You may then cover it with carpets or tiles which can be easily removed later.
Jan
