If it's quite in the room you'll hear it start making a funny noice. I also put in more cotton than if seen the other guys do. When I wick it, I leave about 1cm om each side and fold that in between the posts.
Also check that your silicone pipe don't block at the bottom of the bottle. Cleaned my Reo this morning and had trouble with dry hits. Turned out the feeder tube was block in the bottle and not enough juice was pumped.
I've tried a para coil yesterday. 28g came out at about 0.8 if I remember correctly. Still prefer my 28g, 1.5 id 7wraps. It just took too long to heat up, with no real advantage.