For single-mode lights, I appreciate the tailstanding feature.
For my multi-mode lights, I'm frequently changing output levels to adjust for changing lighting conditions and I'm often using the flashlight one-handed (my dog is on leash with the other hand). Many of the tailstanding lights are not-so-easy to operate one-handed, e.g., D10, 120P, Incendio. They are not hard to operate - they just aren't as easy to operate as some of the flashlights with tactical switches.
(I've switched out the 120P's flat switch for a tactical switch. I've added a button to the D10. The ease of use, for me, has greatly improved. As for the Incendio, I'm waiting for stock to replace the switch cover. My guess is that the improvement will be equally rewarding.)