Great discussion, but somewhat bewildering for mere mortals like myself!
I've just placed an order for an Autoprop on the basis of
1. good customer service from Bruntons,
2. I know it fits and work because many (maybe most?) other 54's have it,
3. I could see no compelling reason to choose differently.
It won't be fitted until next year. In the meantime I need to consider whether I need a rope cutter too.
Amel 54 #154