Nearly all other taillights are powered by replaceable AAA or AA cells. The Hotshot is powered by a non-user-replaceable Li cell. One has to wonder how long this cell will last, because in a light that sells for $33 shipped, it is likely this is a cheap cell. I have had cheap Li cells last for days or years.

Most of the other taillights will continue operating in rain, which is apparently not always the case with the Hotshot, based on comments in that thread.

Finally, although the beam of the Hotshot is very bright, it is a very narrow beam for a taillight, with no spill whatsoever. You'll be visible only from directly behind with the Hotshot.

Those are three compelling reasons to consider lights others than the Hotshot.