I bought a Fontenille Pataud "Rouen city" knife 3 or 4 years ago. It's a slip-joint with about a 3 1/4 inch blade.
It does look nice and it has a handmade feel to it, especially in how the scales are rounded and contoured. The fit of the scales to the liners to the backspring is pretty good. Mine has some nicely figured burl wood scales. There's a little bit of file work on the backspring that is well done.
The opening of the blade is gritty though and there's a massive amount of side-to-side play when the blade is completely open. The grinds are okay, but the blade is too thick for its width, so it's not a good cutter. The blade also lacks a kick, so the edge slams into the backspring when you close it. (Placing a piece of cork inside the handle to protect the edge from the backspring doesn't work on this knife, BTW. Doing that prevents the blade from closing far enough and leaves the point exposed outside of the handle.) I don't think the backspring is necessarily weak, but the blade folds too easily for my tastes, probably because of the shape of the tang.
The presentation box that came with the knife looks appealing, but it's poorly constructed. The box is covered with a blue velvety material and has an oval leather insignia on top. It seems very impressive, but it's actually just made of cardboard and taped together. The leather slip-sheath that came with it is pretty nice though.
I don't remember exactly what I paid for the knife, but I think it was around $120. Fontenille Pataud knives are not inexpensive. They do look very attractive, but I won't be buying another one. I personally expected to find a really well-made knife for that price and mine just has too many serious problems to overlook.