I bought a pax2 and a vapcap m. Love the vapcap and sold the pax2. Felt you needed to vape whole bowl to get the best from it? My choice is either firefly 2 or the boundless cfv. I want effeciency and to take a quick vape or 2 and set it down. They both get good reviews and the boundless is an excellent price. So really is there much difference in them to justify the price. I am swayed to boundless also as the chamber is hidden which is good for all day use out and about.