TL/DR Version: It works pretty good at a darned good price.
Longer version:
I use one of those and it works quite well for 10 gallon batches. I do HLT on top, my picnic cooler mash tun sits on 2 cinder blocks to the side (until I build a small table for it out of wood). I heat strike water in HLT above, drain with a hose to my cooler, then when I sparge I drain to buckets and pour into my boil kettle on the first tier. (If I do the table for the mash tun right, I THINK I might be able to drain right into boil kettle, just haven't gotten around to doing it, and keep thinking I may invest in a pump for that purpose before I get around to building the in-between tier.)
So basically I'm saying, it's a pretty workable setup, and the price is right. With pretty minor DIY, you could tweak it to be a single tier that also would work.
Jet Burner gets stuff to a boil quick. It IS pretty loud, and I have no doubt there are more efficient burners out there.
I will say, after about 2 years, I have started thinking about building a different brewstand; but I think it's more likely I'll be adding a pump to the king kooker stand and keep using it for a while yet, while make a few other equipment changes first (new brew kettle to step up to 15 gal batches, for instance.)