I purchase from Treestuff, Sherrill, occasionally Wespur and Baileys and mainly my local supplier, Sheppards.
I believe that competition is good. I would dislike only having one choice.
I support my local guy quite often, because he's local. Nothing beats needing something for tomorrow and picking it up today. He has good rates, treats me great, I don't have to have stuff shipped or worry about the dollar conversion. Unfortunately I tend to buy more cause of impulse.
I like the variety that both Treestuff and Sherrill have to offer.
Was a little disappointed in both companies at last years TCIA Expo in Pittsburgh though. Sherrill for not bringing product to sell and it seamed that by Treestuff holding their venue away from the convention center, they were benefiting from the Expo but not supporting TCIA. Imagine if all the vendors did that?
Perhaps they have their reasons. Maybe it's not cost effective for Sherrill to bring all that gear and employees to a convention and perhaps Treestuff is miffed with TCIA for stuffing them up on the second floor away from all the action in Hartford the previous year. Would be interesting to know. I was disappointed to bring all that $ to the show and not being able to spend it.

Bickering & airing dirty laundry between two people (companies) only makes both look poor. Don't tell people what the other guy is doing wrong, tell me what you're doing right. I believe that was the intent of Sean and Kudos to him for doing that.
I enjoy the enthusiasm that both companies have for what we do.