I got Rodaidh at 6 months and he was kennelled up until then, it hasn't been a problem at all but his breeder operates a different set up to the one you are referring to, it's on a smaller scale and he does pretty much all the looking after himself rather than lots of kennel maids. Rodaidh wasn't fully toilet trained when he came home but it only took a couple of weeks until he was 100% clean in the house and he wasn't afraid or nervous of household noises, cars or other people at all. I would definitely have another kennel dog again but only from a breeder which I trusted and was happy with.
I'm pretty sure I know which breeder you're talking about as I live about 10 minutes from them, and if it is this one then I meet a lot of their dogs around here and they generally seem like nice dogs although on speaking to the owners most of them do say they were rather taken aback when they first saw the set up at the breeder's place and do I know of one person (a very reputable working cocker breeder) who had a bad experience with an older dog from this place several years ago. From what I know and have heard if I was ever looking for a show type pup I would not go there, I would find a smaller hobby breeder. This place for me blurs the distinction between a good show breeder and a large scale commercial breeder too much.