Hopefully Jeff H will weigh in here for you, scove, he seems to have a lot of knowledge of these boats.
There was a Vancouver Whitby 42 that did some extensive Pacific cruising in the '80s, it was called Feng Shui and was sailed by Jim (dammit, forget his last name - he works for the city now and was on the news during the Stanley Park storm coverage...) If you can track that story down you may get some more info.. it was covered in back issues of PY.
I can only tell you anecdotally that AFAIK
they are well regarded as serious blue water vessels assuming you get a good one. I understand there were variations produced as a Brewer 12.8 too.