Blindasabat hit it on the nail. The ergonomics for one-handed operation is better on the P1 and the price is considerably less if you don't care about the AA/14500 compatibility. My Jet1 is pretty easy to turn, so I don't mind the smoothness, so I would prefer more grip. I also like the feature of the sapphire window, but that may or may not matter much to others. I prefer the styling of the Jet1 over the P1, but that's also personal preference. As Blind stated, it's the brightest, whitest LED light I own in an extremely small package. It impresses everyone I show. I also love the dark grey finish. Now that more competition for the ultra-small 1x123A twistie lights have come out (along with more competition for AA lights), were I to do it again, I would've likely not gotten the Jet1 and would get a Luxogen LR5-3W instead. It offers very similar styling, has the same smooth-head issue (an o-ring works great, but like my Jet1, the Luxogen is easy to twist, so I haven't had probs with it's smoothness), great features such as glass lens that competitors in this lowest price range (like the Ultrafire WF-602D) don't have, and costs considerably less. The P1 tho is still very well machined, has very good HA, and twists easily due to the knurling.