Vitolo knows yo, I've had my No2 for 1 1/2 years. She Works like a charm.
Here's what I do and my No2 produces great tasting vapor. I use the clear mouthpiece only, the tube that comes with the No2 just doesn't work for me, the heat up time for this device is under 3 minutes with the battery and under 1 minute plugged in.
However, I like to wait up to 7 minutes sometimes just so the chamber is extra ready, just my preference. Given I vape around 2-3 bowls max when I use my No2 in one session. Vitolo is right about it not being for cloud chasers, but the vapor speaks for itself, it's rich in flavor and the density of the vapor is very nice. Think of it like a mini oven, the longer time between hits the tastier each hit. I tend to go around 10 seconds between hits, and they are TASTY tasty hits.
Good luck with your hunt