I love my Vision. Bottom vent needed a little modification to better control airflow, but since then it has been a low maintenence cooker great for smoking.
@ fingerlickin - When my top vent sticks I just throw on a pair of thermal gloves, grab the base with one hand, the damper with the other and give the damper a little jiggle up and down (I guess I just like jiggling things...). Comes loose easily. No need to bang on it and risk damaging the ceramic.