I've wanted one of these for weeks, finally I got round to getting one from Regis Salon located inside the House of Fraser store on Oxford Street. I paid a tenner for the neon pink one.
It's absolutely superb, my normal Denman brush rips through my hair, which concerned me as it is very long (waist length almost) but I want to grow it longer.
The TT seems to unravel knots really quickly and gently. Like another poster mentioned, on thick, long hair you do have to section your hair to brush it all, but I had to do that anyway with my regular brush so I don't mind.