
I think it depends a lot on the dogs - we get two danes in at work, one handles it wonderfully and is quite happy (although he doesn't like holding his bladder first thing... makes quite the little lake in the kennel!!), whereas the other is very antisocial when he's in, he doesn't like going back in and he will growl if you touch him. They both eat well though. The one other dane we've had in did very well, very happy with the place. Sadly she died though, she was a very old girl last time she came in.
I do think kennels take a bit of getting used to - my own dogs (not danes) weren't at all impressed the first time I put them in, but now they are fine - they have been in many times now, they've gotten used to the surroundings and the routine. I think if you can afford it, many short stays are a good way to get them to adjust - it's something I'm going to do with any new dogs I have in the future, whether I have the advantage of working in kennels or not.