I just purchased a Spotted Saddle Horse, which is to a Tennesee Walking Horse as a Paint is to a Quarter Horse. Same gaits, but a different coat.
I have also spent time with Walkers and have green broke a few. The guy who owned the property i lived on in Alabama for two years was a Walking Horse moron. He trained them with weights, pads, acids.. (may i mention some mysterious person may have just called the Humane Society on him

) Im so disgusted by the show industry.. and how they bred the original purpose for the breed out of the horse. They were meant to go ALL DAY and be a smooth ride. Now they can only ride for 15 minutes a day, and go incredibly slow, though they take longer strides. I cant stand what they have done to the breed... but thats not what this thread is about ^^
The Walkers I dealt with were pretty inconsistent. There were a few Merry Go Boy mares that were EXTREMELY psycho. But, they were bred for their pedigree, not for their soundness or temperament. She was unpredictable and wild. It literally took -nothing- to set her off into a skiddish frenzy.
But, there were others that were absolutely fabulous. One mare hadn't been handled for all 3 years of her life, and i gathered her up, saddled her, and rode her the same day.
Keep in mind, all the horses I trained weren't even touched by human hands until they were 1 to 6 years old... so i guess thats kind of a variable =)
Could you tell me more about the one your looking at buying, if ya picked one out yet? A lot of the time, the horses past has allot to do with how they will perform for ya.