Really - the thread is an exercise in splitting hairs. If you buy a high quality 200 lumen flash light - you will most likely want to run it at 200. However, I have on occasion turned my LD20 down to 100 lumen just to see how lights "used to be."
The two biggest points of the thread, you have go Li Ion for more power, there are lots of choices if you put up with short run times.