Very efficient. If you're on the fence, it's worth it.
Loved my b0 but with glass injector bowls I had to use a ton of flower (due to bowl diameter more than anything -- I remember the 14mm injectors being better in this regard) and I really only got one or two huge hits. I don't think it's necessarily less efficient, but I just don't need that much herb. With this, I can get 6 or 7 moderate rips a bowl, and pack it much smaller if I want to. It's much more efficient. Reminiscent of log vape efficiency in ball vape form factor.
This is pure convection with no conduction. Just to be clear, because I've seen mixed or wrong information before. I personally find this very nice -- Ed's bowl simply stops producing vapor when it's finished. You just choose your temp, and pull off the compounds you want. Super nice for me, as someone that only consumes CBD flower for low back pain these days. The higher temps CBD comes off at mean that if I accidentally rip too hot I might combust. This bowl prevents that entirely.
Glass bowls do heat soak, contrary to popular belief, and allow a mixed conduction hit. I can in theory keep ripping harsh, charry vapor on a glass bowl long after the bud is fully extracted, because the added conduction allows for higher temperature hits than I really wanted in the first place.