As has been mentioned in previous posts, any given brand of paint is only as good as the
local support you get with it - at least, from the contractor's perspective...
This makes some brands the #1 choice in some regions, when the same brand could be the LAST choice in others.
BM tends to do very poorly in this regard when one is dealing with the mom & pop hardware stores or otherwise non-dedicated paint dealers.
Personally, my most skilled tinters & color matchers are at my local independent BM dealer - so they get the majority of my business. My local ICI is competent, I go to them whenever I need the 4216 or something BM doesn't have. My local SW is a total joke, they can't mix 2 matching gallons to save their lives, and they SO don't care whether I buy from them or not - so I don't.
In the end, as long as you're using an appropriate paint that
you like to use, you have the best chance for success.