I ordered from ebay scratch and dent sale site. The GMG Pizza Oven arrived with a little damage to the box and one cover tab was slightly bent. But for about $60 savings I would definitely recommend purchasing scratch and dent again! The fit was perfect no adjusment to the tabs needed.
I usually set the RT-700 to 415 degrees and the pizza oven hits around 700 degrees before putting the pizza in. The pizzas came out really good. A wood peel will help with sliding the pizza in and a metal peel for turning and pulling the pizza works best. A good infrared thermometer is helpful to checking the temp of the stone and inside the pizza oven.
As @sdynak mentioned, make sure you don't get the smaller one. There is a video on YouTube of a user who modified the smaller one with some vent duct pipe to fit, but he could only cook little personal pizzas on it. It was pretty funny!
I would recommend the 380x with a steel. I bought mine so that I could keep the rt700 for low and slows and the bullseye is so much better at high heat and grilling. With the steel set temp at 600F and preheat 10 minutes then cook 10 minutes pizza is perfect. The 380x gets used almost every day because it's so easy. Love the ash dump system the most.