This is all very interesting to read, having come across this thread 12 years later, having been searching for "Detania". I bought a pup from Angela in 2008, so around the same time as the OP. He's our 5th Border Collie and the best to date. Good natured, gentle, quick to learn, easy to train, good with children and strangers and healthy - even into his 11th year. We have been very lucky to have him. I hope the OP was not put off by some of the above posts and has been as fortunate as we have been.
We got to meet the dam and sire and they were very good natured dog - dad was still the biggest collie I've ever seen and out Ben has taken after him, although he's still one size down from him.
We shared deep misgivings about the "Gremlins", but there was absolutely no evidence at all that any "contamination" in the BC line, with certificates for BC KC registrations going back for 5 generation
Sadly, Angela died several years ago and her husband continues, alongside Angela's daughter. I was keen to see any evidence of the quality of their breeding since Angela died but, other than the fact that their presence seems to have moved from their own website to pictures of "cute puppies" on Facebook (not a good sign!), I can't find any reliable information that's been published since Angela passed away. Has anyone any recent experience?