Thanks for your post.
I'll start with what I mean by "fitted", this is some work on the bow roller so that the new anchor fits better. When I bought Aphrodite she came with a poorly fitting Bruce that had clearly damaged the gelcoat in the past, so I wanted a bow roller that will keep the pointy end of the Knox away from the hull and make it easier to deploy. On initial fitting the 13kg Knox just fits in the current bow roller and touches the hull in the same place as the Bruce.
Reasons for choosing the Knox:
1) The Bruce was an ideal anchor for where the original owners located the boat on the east coast of England, my plans are for more varied sailing grounds and I wanted a more modern design with more holding power;
2) I made the assumption that all "new generation" anchors especially ones with roll bars will more or less work the same way;
3) Having the anchor made in the UK and purchased directly from the manufacture this has several advantages. I now have a relationship with the manufacture and can return it directly to them if there is a problem;
4) Knox were very open about what materials and manufacturing processes they used. Nothing fancy in their manufacturing;
5) The design is simple and Knox will regavinise and refurbish the anchor in the future if I ever need that done;
6) The design is a series of triangles and as a retired engineer I like triangles for strength;
7) I liked the half fluke or slot design as I hope this will help self clean the anchor as I raise it. I am not impressed with the "ice axe" pick of some of the new designs;
8) Weight. For the size of vessel I would have needed a 16kg Manson Supreme or a 12kg Rocna Vulcan. The Knox is 13kg.
I will see if I've made the right decision over the next few years.