om15, the 748 can't have been that bad as examples worked for years in harsh environments, often with poor standards of maintenance and were often thrashed on a daily basis.
Both types were examples of good design and construction. The standard of many 748s returned to the UK for further use, starting with the YPF examples returned to Manchester for Dan Air, was poor to appalling yet they were able to be placed back in service, again in intensive conditions for many years, then going on to third owners.