I wouldn't attempt to comment on the Grayhawk or the KZ since I've not owned wither of those models but I CAN tell you that my Rockwood Ultralight now has well over 100,000 towing miles on it, traveling through 49 states (many of them multiple times) and it's been as close to problem free as any you can buy. I had only a single warranty issue come up during the second year of the factory warranty and that WOULD have cost me under $50.00 to replace the water flow valve on the Thetford Toilet, had it not been under warranty.
I believe that reliability is SOMEWHAT dependent on how it's cared for and how it's used. I keep up with maintenance before it becomes a problem but use my trailer hard with lots of disbursed camping in National Forest areas as well as disbursed camping in the way to and from Alaska. Otherwise it's campgrounds first (not RV parks) so everything MUST perform reliably.
We made our choice of the Rockwood based on features like 4 season capability for our winter time trips.
Good luck with your decision / Skip
2011 F-150 HD Ecoboost 3.5 V6. 2550 payload, 17,100 GCVWR -
2004 F-150 HD (Traded after 80,000 towing miles)
2007 Rockwood 8314SS 34' travel trailer
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