On Jayco vs KZ, just on the frame, the Jayco is far superior. I just looked at a new Jayco 32BHDS this morning. It has a to-die-for frame that is first class. Extremely well-engineered compared to KZ. It has a one-piece forged beam (not 3-pieces welded together) which is taller. It has 2x2 tubing welded to the lower beam flange in the area of the axles and spring hanger brackets. It has gussets welded above the lower beam flange at the spring hanger points. If I were to design a frame from scratch, this is how I would do it. This is the only nearby Jayco TT that I could find of comparable length to our Spree 261RKS. This Jayco model is a heavier trailer and don't know if their shorter ones have a different frame design. Of all the trailer frames I have looked at lately, this one is way ahead of the rest.
To compare apples to apples with our KZ 261RKS, Jayco has a 266RKS which is very similar. It's a heavier trailer by 900 lbs but has a GVWR that is 1700 lbs more. That tells me that it probably has more substantial construction. Perhaps a stronger frame accounts for some of that. I really hate to say this, but if we were starting over, I would look at the KZ and Jayco side by side in very close detail and more than likely go with the Jayco. Don't know what Jayco dealer and factory support is like though.