I have a #2, 510, 780 and 946.
The blades are so similar the choice is really carbon or stainless, handle style and sheath.
#2 handle a little small for me and no guard
510 is okay but seems a little cheap
780 is nice. It is carbon steel and has a hard plastic handle.
946 is nice. It is stainless with a "sticky" rubber handle (sort of like the resporine of a swamp rat but more so) and the best sheath.
Hard choice between the 780 and 946 and depends whether the "sticky" handle bothers you. I would choose the 946 because either handle is fine with me and the 946 has a better sheath.