Jazz is one of Thor's upscale lines and comes fairly nicely equipped. It's not a brand we hear much about, which could mean they have few problems or could mean that not many are sold. Since I'm an easterner, it is not too surprising I don't see any Jazz on the road (it is a Thor of California product), but I haven't noticed them when we head west either (and we spent 2006 & 2007 summers in Oregon). I will say that the Thor brands are not the ones that come up first when fulltimers talk about buying a new fifth wheel. And not the second either. The top quality brands (some of whom have gone out of business in the past year due to the economy) are brands like Travel Supreme, Holiday Presidential, Teton, Carriage & Carri-Lite, Mobile Suites, NuWa, Alpenlite, New Horizons, just to name a few. [Yeah, I'm sure I missed more than a few brands - these are just examples].
The problem is that most of the manufactures make at least one decent model and there are literally hundreds of model names out there. I couldn't give a definitive list if I tried and it would be out of date when I finished it anyway. Better that you find brands you think you like and ask here about them, just as you did with Jazz.
You also need to pay attention to trailer weight and what your tow vehicle can handle. If you are thinking of buying tow vehicle too, then you need to consider how much truck you are willing to drive.