For me here is a distinct difference in the flavor of wood smoke vs charcoal smoke- even with some wood added.
When I add that into the long term concerns about reliability, only the Smokin' It or Smokin' Tex are simple enough (they only have a rheostat knob for adjusting temperature, and a heating element). That is all that all that can fail. And - you can keep both of these parts on hand cheap enough. They are made of heavy grade commercial stainless and industrial insulation.
They are both imitations - sort of .... of the Cook Shack products - in my opinion and form examination. Not cheaper in quality - but a heck of a lot less expensive.
Those are the things that separate them from the Bradley which also uses a wood "puck" that ONLY Bradley makes - so it is not available everywhere. As well - the moving parts that push the puck into the cooker, and the electronics on the digital model are not robustly made. There are a number of folks here that have owned them, and some currently do own a Bradley. Not knocking it - but it is not as durable a design or construction as the Smoking' It or Smoking' Tex.
I have also owned the Masterbuilt box smoker ( not the current model) and- it and the Char-Broil, and Cajun Injector are very similar in their construction and use of lightweight materials. Both in the construction of the box, and the electronics. This is because we as consumers constantly beat companies for more features for less money - so they have to make compromises somewhere. Common to all of them including the Bradley is the use of spray foam insulation - not industrial "mineral wool" as in the Smoking' It and Smokin' Tex.
But - I want to tell you that I have seen and eaten food from the Red Box Smoker. And - while it uses charcoal - you can run it for 8 hours on one load. That is usually enough for most things, and it is easy to reload when you need. Here is a link to the manufacturer's website:
http://ssomd.com/red-box-smokerACW3 - a member her - has one, and likes it a lot. It is a little smaller than the bigger Bradley's and Masterbuilts, etc...but - how often will you need to fill up one of those completely? And - you can use it - or any of these mentioned as a great cold smoker with eh addition of the Amazen Smoker as well.
One other advantage that it has over all of the others is no electricity required. And - there nothing to short out, weather and go bad. Well made. Heavily insulated.
Hope this helps!
T