They both have their benefits, I usually buy my kits, chargers, engine, and cells on the internet (because thats where I see the biggest savings). I buy tires, spare/option parts fuel (nitro cars), pay for track time bodies, motors, paint any anything I can't wait for at the LHS.
What i can't stand at the LHS is when a product is not in stock, they say we can order it for you. I can order it for myself.
I had such an incident happen a LHS that caters to the general R/C population so they don't carry race styled bodies such as DNA, Stratus, and Mazda 6. But the guy working their said that he can order it! If I wanted something ordered I wouldn't have drove all the way to your LHS.