IMO you're a consumer. They're competing retail businesses trying to make money off you, not tax exempt charities. I say shop around as you have been doing, based on the factors you mentioned.
If you're doing that, any price advantage (and what shop really does that in a meaningful way anyways?) you might get for being loyal would be made up for by the fact you go to the store offering the best deal at the time. And you won't be restricted to one shop's inventory on-hand and having to wait for special orders, or their lack of a speciality with certain brands or tasks.
And from a service perspective if a shop would treat you differently for having such an opinion, that's not a place I would want to spend my money at.