I like mineI get very good results using my smokenator, and Don (the seller of them) is very helpful. I get a very stable temperature.
That said, using this setup, I'm now pretty locked in to finishing my butts and briskets in the oven. You get a nice long initial burn (with mine 4 - 6 hours) but after that its a bit of pain to keep feeding it more charcoal. Once my meat gets to 160, I foil it and bring it inside. So, the way I use it isn't for smoking purists.
I think it was worth my money. If money is tight, go ahead and use bricks or a cookie sheet, but I think I am getting my money's worth out of the Smokenator.
I use briquettes for the intial load, and when I add more charcoal, I use lump. This keeps the less than yummy briquette lighting smoke away from the meat. If I was going to add briquettes, I'd make sure to use something more like Kingsford Competion or Duraflame.