This past week's ROAR Nats offered a really good comparison between the Tekin and BD ESC's. One notable driver drove the Tekin in quals 1 and 3, and the BD in quals 2 and 4. It was a draw. I was temping his motors as they came off, and they were virtually the same (Ballistics in both.) The small variability in times in an actual race environment had far more to do with the track and traffic than the speedos.
The value proposition for each ESC is different, yet equally compelling when the end results are considered. It's just good to have two quality options that can deliver similar benefits.