I had no idea other stores had split up stockrooms. I have a hard enough time teaching my trainees to not waste time running back and forth from our main to the bulk racking in receiving, I can't imagine what they would do with scattered stockrooms. Though it does sound helpful to have BUCK and CNDY up closer to the checklanes.
Our backroom is one big connected unit, spanning half of one side of the store (a small room for HBA), then continuing down a whole side around the corner. Our main stockroom (1-18, some A, B, C, D block and softlines, a separate locked room for electronics backstock, as well as all PFresh related stuff) and receiving (3 levels of steel, large/bulk items as well as light duty aisles for market and seasonal) are only separated by a fire aisle. The only time I have to go on the salesfloor is to get to the break room or to bring items out for guests. It's a good system, but guest services is literally on the opposite side of the store, and on a busy day when you're stopped to help guests five times in between, it's a pain.
We're not a high volume store, but visiting ETLs/BPs/whatever are always amazed at how tiny our stockroom is. We can get a little tight on space during the busy times of the year.