Synthetic fibres -- objective performance ratings?

[Renoir]

Sorry Dan, I should have qualified further the reasons for my liking the Carrick bend. This bend is easy to tie, easy to untie and strong and can be used with widly varrying diameters and types of line mixed.

The bends that you mentioned are qualified by their being confined to using lines of fairly equal diameters. The Grapevine can be a bitch to untie after it has been subjected to a heavy pull in water. I do like the symmetry, however, of those that you mentioned. I truly don't know how to choose between an Ashley #1425 and the Zeppelin or Rosendahl's bend....any suggestions?
Thanks