PD40 pros:
- Fairly compact form factor
- Fits nicely in the hand for hiking (better, in my opinion, than 18650 lights - think C cell Mag)
- Decently bright for its size
- Can run at 1000 lumens without a stepdown
- Nice tint (as you would expect from an MT-G2)
- MUCH longer runtime at comparable brightness vs 18650 lights
- Unlike other MT-G2 lights, no need to worry about multiple Li-Ion cells
- Makes a nice lantern with the AOD-M diffuser (GREAT in a tent or during a power outage - especially with the long runtime)
- MUCH nicer beam than XM-L2 triples (like the Foursevens MMU-X3)
- Can tailstand
PD40 cons:
- Burst mode requires you to constantly hold the switch
- Burst mode does not work when battery voltage is below about 4.0V
- When switch is held down to activate burst mode, the light turns off for a second before burst mode comes on
- Somewhat cumbersome UI requires cycling through all brighter modes to get a dimmer mode
- Longer cells are a somewhat tight fit if you are uncomfortable with unprotected cells
- Although decently bright, not as bright as most other (multi-cell) MT-G2 lights
- For those who consider it important, no moonlight mode
Although the PD40 is FAR from the perfect light, I feel that it has ALOT going for it. If you like the 26650 form factor and want a nice, bright, compact light with a guaranteed good tint, this is THE light to get. Plus, you get the extended runtime of a 26650 (and 26650s tend to be more conservatively rated than 18650s when it comes to capacity). And it will run at a real 1000 lumens for as long as the battery lasts (unlike smaller 18650 lights).