rotary is the version that is sold most of. Hogo mentioned it is ~9 rotaries 1 Clicky ratio....
Long time ago I made a review of the regular Body types of the Rotary (CR123, 18650, 2xAA) in a german forum. Important the measurement is metric!
And a size compare with the Surefire Outdoorsman lights (2xAA, 2xCR123, 1xCR123)
That is the most difficult question since there are mostly some preferences, like warm color, or a cooler color, ....
A lot people will say NB45, and I agree with them, NB45 is great. But I personally prefer the NB40 a bit more. But that does not mean NB45 is bad!
Only to give you a feeling about the colors here an old picture of a compare of HDS LED options taken in mid 2018:
The Nichia 219C and the currently offered 219B are somehow comparable. The 219B is mostly a bit more rosy due to the fact the white light has more red.
Here is a compare of NB30, NB35, NB40 and NB45 I took in September 2022 on request.
Also in this thread are some smaller light color compares of other members of the current LED options, but for this you must search for it on your own.