Um the only i can verify is the Q3.
I Have 2, and run them on Protected Li-Ions in the 750mah version, they are from john at
www.lighthound.com whom i can recommend with confidence.
He sells a couple style chargers too that are compatible with these batteries aswell, a Nano (Single Slot) and a Double Slot version aswell, keep in mind i believe they all charge one cell at a time then switch to other when one is done, likemy dual slot charger.
Difference in output of light is noticeable, makes a new light out of an older one just by changing batteries.
For every single cell light you plan on converting to Li-Ion, consider getting atleast 2 rechargeable batteries for it to use, one for back up , and always charged. Aswell for any mutli celled light double upon cells, Note only some multi-celled lights can run on 2 123's at the higher voltage an get away with it, like my E2L, It loves its Li-Ions, more output, brighter ect, in fact so does all the lights i use them in.
The X5 and the Dorcy i can not comment on as i dont know, sorry.
I am really suprised no one took 2 mnutes to answer this so far.
I am sure someone will add to this now bro, so be patient.
Peace out
IF