Philbky, yes you are right, the 748 was a favourite in Canada and New Zealand for example, I once went down to Zambia to bring an ex Zambian Airways 748 back and the airline were really sad to see their Avro go as it had been so reliable.
My comments were only slightly tongue in cheek, the 748 did have some pretty dreadful design faults, resulting in gust locks engaging during take off and occasionally the nose leg coming adrift, admittedly these can be attributed to maintenance actions, but the potential should have been identified by the manufacturer.
The trials at Boscombe Down that shortlisted the Herald and 748 for the RAF came out in favour of the Herald, however the politics of the day overcame the performance results and the 748 was chosen.
IMHO the Herald was the better aircraft if reliability and maintenance costs were considered, but as you say, many airlines swore by the 748 as a good reliable workhorse, and the ones that finally kept going into the 1990s had certainly earned their keep.