I've really enjoyed my m420, but I wanted to be able to see the bowl. Sidelighting the bowl always seemed to leave some unburnt material by the stem. With the Mycroft chamber attached, no problems. It does have a couple of negatives. Due to the air path, it does need cleaned more often. The legs work, but it's pretty tippy. I'd just as soon had the leg-less model to easier fit in a pocket.