Also limited by temperature
The Cree X5 uses I have 4 CR123 batteries, the P7 takes 4 AAA. the burn time on the P7 on economy is over 100 hours which i can confirm as I use it all the time, used it last night. I use the P7 because I wanted to limit battery types I have to carry, and try to make them all the same size which thankfully I have.
I also use the P7 because its small, robust and light and 200 lumens suffices for what my needs are as I said before when Im looking for someone I use a dog much more agile, intelligent and powerful than the torch and human eye...It was a search dog that found the missing person last night
Many of my colleagues use the P14 and have nothing but praise for them and each search section carries a X221, now that the novelty has worn off its not something many would reach for very good at scene/incident lighting though