I agree about the service in EBC, I've often been left with no-one to talk to

it depends who's on at the time - if it's some callow youth with a love of bicycles but a fear of people you might be in for a long wait.
That said I did once manage to talk to someone with an intimate knowledge of pumps and ended up a very happy punter.
I'll also mention Butterworths round the corner: could not be more knowledgeable or helpful but he only offers a limited range of products. And have you tried Recycle Bikes. Top notch for repairs, never seen anything like it.