My guess is some people choose Taylor K2006 since it's conveniently sold on amazon (and perhaps at the pool store?). I heard one person say they dont like the Tf-100's awkward fishing box. I can see what they mean but I've been using the TF-100 for 5 yrs and that's what I'm used to, although I do need a new kit and was thinking of seeing if the Taylor K2006, or any other kits for that matter, are just as good if not better. I also heard that TF 100 has more to offer as far as what can be tested and it seems less $. I also wasn't quite sure if proceeds from TF 100 might support TFP? Any other quick thoughts? thx!