I use a Memphis Pro and really love it. It smokes at 180 degrees and up... and also grills at 650F.
The smoke flavor is lighter than my horizontal wood burner, drum or block pit but it's still there.
Here are a couple of pork butts I smoked not long ago..
I really love the thing.
I forgot to mention... Brethren Big Poppa has a great selection of smokers if you're interested..