I was lucky in that I got to borrow a Bender and sort-of learn to use it without making the investment, which is quite a bit! I really messed up my first few bowls and combusted towards the end probably the first 10 until I started figuring out a draw, puff and timing thing as well as stirring it several times instead of just once through a session.. I certainly didn't master it during my short affair but it certainly planted a bug! In retrospect i wish I had tried clicking the top on and off more to get better results. It can deliver quite strong and flavorful- what some call "full spectrum" maybe- lungfuls of vapor. I used it about a dozen times so I don't have the experience of an owner.
With that said, in my opinion, or lack of experience, there are a few drawbacks. I found the best hits to be with quite a strong draw and the draw will (especially towards the end as the very dry herb is broken up by your stirs) cause a lot of plant bits to get drawn into your mouth! UP Tech recommends the use of cotton in the mouthpiece- If they mean to make a ball and shove it in the tip of the mouthpiece, the cotton inevitably ends up on your tongue. I found using a screen right on top of the herb before adding the mouthpiece worked best, and hated that; I didn't use a metal screen in an all glass piece with enthusiasm. The vapor is of course dry and the mouthpiece isn't the easiest to attach tubing to. Although you could, I suppose, fashion a mouthpiece-replacement piece for the top fitting and do something different. (I have come across pictures from older pages with very interesting looking Bender contraptions)
The flavor from the glass airpath is too tempting, the effects nap-inducing. I'll have to get one eventually. But not until I have a Core or Iris to lower the temperature of the 1200 rod a bit. (The other rod wasn't hot enough. 800f?)