I have had both knives, and they both have their merits. The Manix is INSANELY light, quite possibly the lightest full sized knife easily available. The Endura is light enough to be barely noticeable and takes up very little pocket space. The Manix is a little more expensive, has a lower grade blade steel, and is likely weaker (but upon holding the knife you can tell it is an EDC, not a beater). The Endura is heavier, but has steel liners and a more solid clip. They both make good EDC knives, but the Manix is easily a lighter duty knife than the Endura.
If you need strength, get the Endura. If you need insanely light weight, get the Manix. I had both and liked them both.