Ive gone from a Poldiac to a JM22 now to a Paps 2.5, best choice i made, the paps just feels good in the hand, the button is a dream to use, simple as can be and just works everytime without fail.
Poldiac was good, but god damn it was fiddly as hell to clean with all the silver plated screws and what not, again this suffered Voltage drop because of dirt build up on the contacts and being silver plated was a pain to remove.
The JM22 i had nothing but troubles with the button, it only fired correctly pushing on the extreme edges, the middle just arc'd and you could hear it popping, voltage drop was terrible due to that, 4.1v unloaded to 3.2v with the atty on, JM replaced it, but the same thing, so ive given up on that and use the JM22 tube with my Paps top cap and button, so really i have a JM22/Paps 2.5 hybrid lol.
Obviously with a Kayfun Lite on top, the best purchase ive made, my coil and wick are still going as good as the last day i coiled it, which was 9 days ago, vaping a very dark juice FUSA RY5 which is almost black. Had the kayfun almost a month and bit now, and its never let me down apart from my ability to coil it at times.