The Endura 4, Centofante III and Native III (the VG-10 one) are my favourite FRN Spydercos, I rotate between them quite a lot. As has been pointed out, they are quite different knives.
The Endura has a larger blade (and is of course larger overall) and is sturdier than the other two. The new version with screws instead of rivets, steel liners and reinforced tip is a great hardworking knife. It is big, but it is still quite light.
The Centofante III is like an updated Opinel. The thin blade will slice through anything with ease, the handle looks a lot nicer than most FRN Spydies and it is so thin that you will forget its in your pocket. It has a kind of gentleman's folder feel to it.
The Native III has one of the best handles I've seen in any folder, even though I have big hands it fits me perfectly. The blade is a little shorter than the other two (it has a choil which takes some cutting edge). I've put this little guy through hell and it worked like a charm. It's a great medium/smallish working folder.
The choice between the Endura (it was the Endura 3 at that time), Centofante III and Native III was so hard for me I ordered all three of them. A killer deal for less than $150. If I had to choose one it would probably be the Endura because it's more versatile and the recent improvements are very good, although the Native would be a close second.