I agree that having carts in a store - like JoAnn and WalMart makes it a lot easier to buy more - and it's nice to be able to see everything together.
Some of the LQS I've been in, though, barely have enough room for ONE person to walk through the aisles - holding their arms close to their sides - - -
I also do not care for shelves that seem to be over arms length high off the floor (I'm only 5'3") - Some stores do have stools to stand on - but my balance is getting a little iffy
I can see storing duplicates 'up high' - some stores do that -
The idea of a 'resting place' is nice too. The LQS in Dade City has a nice bench right outside the store and one or two chairs off in a corner - the longer I stay, the more money I'm apt to spend.
It is also nice to have a place for the 'non-quilting companion' to hang out while the quilter shops.
A rest room available to the public is nice, too.