I've had a KZ 27TH (Toy Hauler) for nearly 4 years. I have only had a couple of very minor, expected type of issues with it. It is not real fancy, but has all the necessary stuff. I find it comfortable and reliable, and it has held up really well. All the KZ's have Lippert frames, not sure if they are of the same construction mentioned above, but my welds all look good and the frame build quality looks really good also.
KZ has been awarded the DSI Award many times over the past several years. Good luck with your new purchase.