I'm not known for being brief but I'm hoping the pictures will do most of the talking and I'll just have to fill in the blanks. The teasers above should give a little information as well.
Basic Specs: 5" blade, 5" handle, 1/8" O1 tool steel, 1 1/4" tall blade, saber grind.
Overall: Great knife. It was a lot slicier than I expected, it performed very well in the kitchen considering 1/8" steel and saber grind. It could be the nice edge it came with from Ty, but that means anyone that can sharpen a knife well can make this thing stellar for food tasks. Think, camp kitchen knife, hunting knife, Kephart's original design intention, or a general purpose utility knife.
Blade: I think this is the magic on this one. It has the spear point and shape very reminiscent of the Kephart knife design/philosophy but with a saber grind. The tip is good and pointy and there's enough belly to make slicing easy. There's also a lot of flat section to do all of the woodscraft tasks.
Ergos: Not bad, but this was where I liked it the least. It was a bit small for my large mits. If you have medium sized hands or smaller, you will be golden. If you like smaller handles but have large hands, I think you will also like it. If you like big handles like I do, I would ask John to make it a little bigger (taller or wider). I've requested an additional 1/8" extra material on the bottom, contoured side of the handle for one I've ordered. I think many could ask for slightly thicker micarta or liners (if John does liners still, I've never asked) and you would probably be set. If you're not hard using it, it will be fine. By hard using it, I mean cutting materials like dried wood like that from deadfall. John's Kephart has a slightly girthier handle, which I like a little more, which makes me think it's probably a small adjustment to get the mud turtle right up there in ergos. The overall shape is good, smooth, and allows many grip positions. Because of the smoother contouring, chopping isn't the most secure but not too many people use 5" knives of this weight to chop. It can do it, but not great at it, and the handle will want to slide a little without a bigger pinky hook seen on many other knives. The pinky hook is a deal-breaker for me, often time, on other knives because I find it limiting on many things, and I hate the hotspot it creates on my pinky, or my palm when using a chest lever technique.
Handle length is great, love this aspect and makes up a lot for the slight lack of girth.
Comparing to a BK62 handle, the knife I would probably most closely compare the mud turtle with. Both blades are reminiscent of the Kephart, slicey but sturdy and intended for many-purpose use. The BK62 handle is thinner but taller, especially around the forefinger, where the mud turtle could use a little more material, IMO.
Performance as a knife: The knife slices really well and I think it would be great at any task that is more slicey in nature than pushing against heavy resistance, like wood carving. About wood carving, this is where I find scandi grinds unparalleled in performance, but they are weak in every other aspect. If you're not going to be doing a ton woodworking, I wouldn't worry about that. As mentioned above, I think the blade performs similarly to the BK62 in that it is very good at slicing and the blade is better at doing a lot of light work more than harder, wood processing, or carving types tasks. It can do it, but not the best at it. The LT Wright Bushcrafter Mark II with a high saber is my favorite bushcraft/woodcraft knife and it is very similar to both the BK62 and mud turtle in this regard as well. I also brought my 5160 buck 119 along, using it and the other knives to kind of calibrate my senses so I had reference points on the material I was working to compare with the mud turtle. This is something I do with all of my new knives, see how it compares to a current favorite in my intended use category.
Conclusion: The mud turtle is a great most-purpose kind of knife. It excels at handling most reasonable things you would ask a knife to do, and a few things you might not expect to use a knife for, but you do anyway because it's what you have on your person, for convenience. I think it would truly excel as a hunting knife, smaller butcher knife, or camp kitchen knife. It will serve well as a bushcraft knife too but I think the scandi ground knives do perform better for this type of thing than the mud turtle, or even the JK Kephart with its convex grind. Outside of carving, shaving, and chopping dry hardwood, it's fantastic and something I would highly recommend to most people that do not have big hands. If you have big hands, I would recommend asking for just a touch extra handle material to be left on there, not much, but a little.