I'm loyal to what feels good and fits well.
Whenever I've been a player or a teaching pro on a free list or on ad staff or signed an exclusive use agreement with a company, I've been fiercely loyal.
But if it's me paying for something and I'm not "SPONSORED", I'm kind of loyal to a sale rack, as long as the product is quality. I think it's silly to pick something on name alone....kind of like the poseurs who pay full retail for head-to-toe outfits. Weak.
That said, I use a Babolat PSLtd, so I got a Babolat bag, which is rugged and functional. I also love their shoes.
I lean toward the historic Italian and French clothing manufacturers, unless they fit weird. Diadora and Fila are great, and inexpensive, actually. Tacchini is the coolest, and sometimes it's even on sale. LeCoq Sportif is a brand I always loved as a junior (thanks to Ashe and Noah), and if you can find it, it's still very cool.
I'm totally loyal to avoiding Nike -- the WAL-MART of sports. No thanks, as much as I love Pete, Courier, Mac, Stich, Andre, Rafa and Roger.
The other stuff like adidas or UnderArmor ... maybe, if it's on sale or if it's something I actually need.
Well, that's my opinion.
Peace.
--sbc