Thanks for the informative reply.

There is certainly a large price difference between a 2kg Danforth “type” with rope and chain (around £40) and the newer designs like the Rocna 4 or even the Fortress FX7. One in an acceptable price range is the Guardian G-7 but as you mentioned, you only use it as a secondary anchor. I guess I need decide whether the cheaper anchors can be relied upon. The aluminium designs also seem to be bigger in overall dimensions and so with that comes the issue of storage?