I want to update my incan Z2 with a drop in that has a Q5. I read some of the other posts, but it seems that the drop in's arn't very straight forward. People seem to have issues with the head not tightening/sealing fully, different runtimes/brightness depending on the number of level settings, heatsinking, beam quality, and actual output. I am looking for somthing with maximum throw, good beam and build quality, two or three levels/settings would be nice, and mabey the ability to use rechargeables. Would I gain anything (other than run time) with a cell extender, esentially making it a 3 cell sf. Also, I see alot of the lights have a strobe mode. I am not a big disco fan, and I don't think it would stop a mugger, but I was wondering if has tried detering a on a lose dog with one. Everyone in our neighborhood seems to have 2 dogs, but no leashes.