Same here with regards to the Lemo, I have to turn the power up to 35 watts or so to get decent flavor. I think the chamber is just too big.
I'm having problems with my K4 vapor-locking and drying out the wick. I have to crack the fill cap to get any bubbles! I'm not sure what I'm doing wrong, I've got the wicks tails trimmed down to hardly nothing, and they're bearly touching the deck!
edit: when the wicks are wet, the K4 in TP mode is absolutely fantastic!
Please forgive me for asking, but you didn't forget to turn it clockwise several times until it stops to open-up the juice flow, did you?