We have two in our area. Both are in 'strip mall' areas. Both are knowledgeable. One has a great stock of RC stuff, especially aircraft and associated equipment, the other does not have a good selection of RC stuff. So, my answer was 'sometimes' for that reason.

Just about all of the large hobby stores, with RC products, that i've been to, seems that the people behind the counter know absolutely nothing about the products they sell.