I'm a long-time lavabox user that recently upgraded to the dual-burner model and a skwok. I was never that impressed when I tried cooking on my old Lavabox (the single burner model). It always produced way too much soot, and the heat was never quite right. The dual burner model has vastly improved that, and I'm now a huge fan of the dual burner models and the skwok.
The skwok put a crust on a steak that's better than what I can get at home with my expensive carbon and stainless steel pans. The temperature control on the dual burner lavabox is surprisingly good, although it's a little challenging to cook at very low temperatures since you can't see the burner when the skwok is in place. The handles stay cool, and the build quality on the skwok is top notch. The best part is that you can cook in the center of the skwok while you keep food warm around the edges. That way everything comes out warm at the same time.
I tried the recommended cleaning and pre-seasoning technique with potatoes and salt. It didn't work well for me since I do not have a gas stove. Instead, I put the skwok in a 400 degree oven for about half an hour, carefully wiped it down, and then thoroughly washed it with soap and water once it cooled down. I then put it back in the oven for about 20 minutes, wiped it down with a thin layer of grape seed oil, and put it back in the oven for about 30 minutes. I repeated this process one more time, turned off the oven, and let the pan cool down inside the oven. This seemed to remove all the wax and leave a nice starter patina. I expect the patina will continue to get better and better the more I use it.
To clean, I pour some water in a cool skwok and boil it over the lavabox. I then carefully scrape any stuck-on bits off the surface, pour off the water, and wipe out the skwok with a paper towel -- no soap! This keeps it clean and maintains the patina to protect the pan. Be prepared for a little soot on the bottom of the skwok after you use it. The gloves that come with the kit are really handy because they keep your hands clean as well as protecting from the heat.
All in all, super happy with this purchase.