I think that one potential source of reported issues with AVOs are that people might not have realised that there are (or were) different stroke combinations available, and that these need to be matched to the suspension movement of the car to which they are fitted. Normally they are(were) available in two lengths, suiting a longer or a shorter ranges of movement.
When I was up at Kevin Vernons back in 2013 installing my Suplex front suspension, we decided to fit a pair of AVOs on the rear as the existing Spax shock absorbers were a bit old and tired. Measuring up the movement on my car to figure out what maximum/minimum lengths we needed, we found that the minimum length required was too small to be able to fit the long series AVO, and the maximum extension required was too large to fit the short series.
Fortunately it was easy to get a set made up with a custom range of movement to suit my car, Tim Ayers of New Elms sorted it out for me and it didn't cost anything more than the standard price.
If people have been fitting an inappropriate length of AVO shock absorber to their cars then it's quite possible they might have had problems.
