The Needs Work is the ultimate slicer. What knife do you know of that has an edge that thin? The FFG Delica doesn't even come that thin.
Its handles are ergonomically perfect for my hands. It is hands down the most comfortable handle I've ever held. If it could be done in a thinner handle, that would be cool, but I think it would lose some comfort. The thumb ditch is also nice; it's placed so perfectly that it doesn't need jimping. The only problem I ever had with it was the clip shape. It made putting it on the pocket very difficult. However, it was cut in such a way that it doesn't interfere with your grip (your hand is barely touching the clip when you grip the knife.) Overall, I think it's one of the best work knives. It should come in a better steel.
The JYD2 is also a very ergonomically-sound knife. I love the knife and don't have many bad things to say about it. The only thing would be that kit's kind of big carry-wise and should have a thumbstud in my opinion.
These are both excellent knives.