Hi, I saw Maglite 3 watt upgrade bulbs at Walmart tonight. I was wondering if I could get the 2D one for my Princeton Tec Predator and how much brighter it is then the oringal Princeton Tec Predator bulb. I was also wondering if I could put the 4D one into my Princeton Tec 40. And how much is the brightness of it in the Tec 40 compared to the KPR103 bulb for it? Can I use Ni-Mh batteries with Mag LEDs too? Thanks a lot for your help. -Beaver II