I knew Brenda before she was a "name." Like in the early '90s. With her you have to be careful because she has a lot of fly dung in her pepper. She also is not known for tollerating views that do not correspond with hers. Tune in on her website and see what happens to views contrary to her "party line."
Some folks whose opinions I respect:
Sherrie Szucs, Ohio. Met her in the early '90s. She steered us away from the heavy shoes, long shank bits, and other things the "experts" told us we must have and do. Don't know what she currently teaches.
Diane Sept, Pensylvania. Long time Walker trainer. Never took one of her clinics, but have seen some good things from her program.
Liz Graves, Minnessota. Have known her for many years. First rate trainer and teacher.
David Lichman, California. I've seen David on multiple occasions. In spite of his embrace of the Parellis he's a good horseman and trainer.
Can't think of any other "names" right now.