I purchased one a few weeks ago and have used it every weekend so far (Pizza Fridays), about 4-5 sessions now. It is a tad expensive but it is well made and I really like it.
There is a learning curve as Mike mentioned, along with the uneven heat situation, but once you get the hang of it the pizzas cook fast and come out great.
Two things - first, I get better results using my own homemade pizza dough and the trick there is to use bread flour over all purpose flour, so much better! The crust comes out crispier. Let me know if anyone would like the recipe. It is only flour, olive oil, water, yeast and salt and you can make it an hour ahead of time. Second, my research leads me to believe that the uneven heat thing is due to the done-shaped kid of the kettle and is easily rectified. You can purchase the $100 accessory from Kettle Pizza that basically places a flat steel lid on your kettle thus lowering the heat ceiling when you are using the Kettle Pizza which cooks the top of the pizza quicker and more evenly. Or you can do what I did and improvise.
I set the Kettle Pizza up as usual but the took the grate from my other kettle and set it on top of the Kettle Pizza. I then took the baking stone I had from when I used to cook my pizzas the oven and set it on the top grate and then covered that setup in aluminum foil and then covered it all with the kettle kid. This creates a lower heat ceiling in the kettle like the Kettle Pizza accessory. It is not as pretty as the Kettle Pizza accessory and I don't think it can achieve super high temps, but it is a $100 cheaper.
Again, I really like the Kettle Pizza because I really like eating pizza. This is the most success I have had replicating brick oven pizza at home and with more practice I think I will get better at it. I am just no where close to getting the 1000 degree temperatures that other users report. The highest I achieved so far has been 700.
Regardless, I am glad that I spent the money and I really enjoy using it. Also, I didn't purchase Kettle Pizza's baking stone. I purchased a steel baking sheet instead since I cracked so many baking stones in my lifetime. I just wanted to ensure that would never happen again. If you like brick oven style pizza and enjoy cooking I think you have to buy the Kettle Pizza. Good luck!