Have both and I prefer the GT purely for the bigger output and wider spread. Wish there was a lower level say 1 or 2 lumens not much to pick on apart from that.
It's temperature based not timer so it will depend on the conditions freezing cold outside and it will run longer. Minor gripe the tactical ring doesn't lock on my sample it did on the XT11S not sure why that is it is a very popular model probably for the high output.