I have a Kiefer 4 horse, the LQ was a shell, so I can't advise in regards to their finished living quarters.

I've had it since 2007, and it's a 2002 model.  I have no complaints with the build.  I travel a lot with it, it tows well, and I do far more gravel roads than I'd like to, averaging anywhere from 6 to 20+ miles of it on each trip I take.  I have had no repairs that I could attribute to gravel roads, and no visible wear because of it.  The finish on the trailer is still excellent.  Some things are aging and due for replacement - the rubber bumpers on the doors, the seized up hinges on two drop down windows - but I think that's pretty minor really.  

My next trailer will have a wider rear tack (and swing out rack!), so that stacking saddles is easier.  I'd also like dividers that are slotted, not solid panels as these are.

All in all, a very good trailer, and its been a good investment for me.