I have been cooking with a Backwoods Smoker (the black smoker on the right in the picture) for three years now and am often asked for opinions about them. I received an e-mail today asking for insight about them and thought I'd also post my response with hopes others will find it useful.
I have the Party model without any of the optional upgrades. I have the standard door, magnet latch, charcoal pan, and removeable exhaust outlet that attaches with magnets. The standard Party model is fine, but it's not the ideal way to go. At a minimum, I would get the upgraded door and latch with the upgraded charcoal pan/grate (similar to the Competitor model). If the Party model is your "dream" smoker and you don't think you'll outgrow it for the forseeable future, I would suggest all of the upgrades offered by Backwoods.
The Fat Boy model incorporates most all of the desireable upgrades (commercial door latch, charcoal pan, door seal and offers a little more room than the standard Party.
If portability and price are not a concern, the Competitor is a nice alternative that offers the space and upgrades. However, the Competitor is too heavy for one person to move around and is awful heavy for two people to move around very much. If it's being mounted in a trailer or will not need to be portable, and your budget can stand it, by all means I recommend the Competitor. I wish I had purchased the Competitor instead of the Party, but the Backwoods dealer near me at the time did not have the Competitor in stock and the Fat Boy was not available from the manufacturer.
One thing to consider is that once you make all the desireable upgrades to the Party, you could very nearly purchase a Fat Boy for a comparable price.
If you are thinking of doing more than a few bbq contests a year, you may want to consider getting two Party's or a Party and a Fat Boy. The Party alone isn't quite big enough to cook the quantities of meats needed for serious competing at bbq contests.
I competed for two years with a Party model and a Weber Smokey Mountain and did quite well. I cooked brisket in the WSM and everything else in the Party.
Hopefully my experiences with the Backwoods Party will help answer some of your own concerns if you consider purchasing one.