OK, got my batteries and ran it all day today. This is one sweet unit for sure. The button is an ease to use. I love that it locks and that's easy too. The construction is outstanding. It's built like a tank. I put a 3,000man 18650 in it and I don't think I have even come close to running the battery out. It's a vape monster too. I know it's just 3.7 volts but it seems like it's more. Possibly because with the bigger battery it stays at 3.7 longer. The threads were all perfect and you can really tell that it's a very high quality mod. The batteries fit very snug. I did have to dial in the button to get it just right. Not all 18650's are the same size the ones I got are slightly longer than most. No problem at all. I really can't say enough about this mod. I will have to order some of the 5volt batteries soon just to try them out.
I think it's more than worth the price. I could honestly see this mod lasting for years and years. Three thumbs up!!!