Neil, whilst i agree with you totally on what an EBT really is.
What always strikes me is that when it is added into both terriers (of different types) or lurchers to produce working dogs, the progeny, we either know or hear about, seems to range from pretty decent to bloody good..! Now though i hate to say it, there must be something in that for that to work out...???
And yer, like i said in my previous post, though i believe that, i'd never advicate the use of one in any line when, on paper at least, there are far better outcrosses out there!