Al posted about that recently. I visited it frequently when I was stationed at Fort Devens back in the early 2000s. I hosted an open house at my motor pool, and afterwards virually all of the visitors made the trek down to STS.
Waiting for me was a brand new Tamiya Dragon Wagon they had all chipped in to purchase for me. Great memories. I taught an old M60A2 tanker how to drive an M1A1 that day.
You aren't kidding about the kits. They were stocked like ten feet high and the aisles were so narrow that a short man like me couldn't look at the kits piled high, nor could a tall man stoop to see kits waist level or below.
The only hobby shops that came close were one on Long Island's south shore that was run by a guy that looked like a leprechaun in the mid 80s and a really old hobby shop in downtown Mannheim, Germany in the late 80s.
Spare Time Shop had more stuff than both of these combined. It really wasn't a neighborhood shop; it was a regional Mecca for model builders.