I have been researching the HECK out of cabinet smokers. I looked at the Onyx but steered away after reading more and more about them. I ended up with one of the 5 or so other GREAT pits out there now.
I went with Superior Smokers SS2 due to the overall gravity fed design but with numerous improvements as well as its competive price and large racks on a failry small cooker.
Again - there are several GREAT quality units out there give a look to Superior, Stumps, Backwoods, Spicewine, Pittmaker. They all seem good....
BGE, Weber Genesis NG,OTS 22" Kettle, Superior SS2, BLISTERING fast Green Thermopen