Well for me the Jumbo Joe I made really works well for home use. It can cook at many different temperature ranges and is very fuel efficient. The minis that are being made are with a 14.5" grill base, the jumbo uses a 18.5" base. So I can do a couple racks of ribs or as much as 4 butts at a time. So it can cook a lot. I have been able to transport it with very little challenges, even with a hard cover on my F150. Depending on what you do with it on the build you could look at a range from $250 on up. These take a little while to get figured out, but are great and extremely versatile.
UDS are a very simple design. You have a barrel with some vents, grates and a fire basket at the bottom. They work great as well, just a little more to move around, but can produce some great food. I have seen them built for as little as $50 and as much as $500 (too many bells and whistles). It does take a bit more when loading and if any adjustments are made, but as you learn the cooker and product, that becomes less of an issue. Once you have them tuned in, they are rock solid on holding temps.
Kamado / Green Egg styles are very fuel efficient and can be very flexible. Some you are tight on cooking space, but they hold temps like a champ. I have only grilled on this style. Moving around is a bit of a chore, you will need 2 people to load into the back of the truck.
Off Sets are one of my favorite when I want to be involved the entire time. Usually they need mods if bought, some a little more than others. They are what most people picture when they hear smoker. I run mine with a mix of charcoal and wood, but mostly wood after things get going. They can be fuel hogs. They are also a chore to move around in the bed of a truck.
All of these have their areas they excel in and have areas that they don't. In my humble opinion, if you are looking at competing, you will need multiple smokers or a bigger one that you need to tow. The last one I did, I used my FIL's Char Griller. But we only had to cook 3 meats. It was very hard to time manage the cooks and ended up over cooking my chicken and pork butts. This year if I do the comp again I am bringing multiple cookers, the char griller and my jumbo mini. This way I will be able to cook at higher temps for chicken and keep things normal for the pork butt and ribs. As I said earlier they all have good and bad, sometimes just need more tools to do the job. I have access to 5 different smokers and use them all for different things.......when the wife complains, I just ask her why we need so many different animals for pets.....