So far I have only used Pfiel carving tools and am accustomed to sharpening them.
I picked up a set of old Mifer (Spanish) gouges today. It is taking me a couple hours per gouge to set their bevels because the gouge is so thick. I read somewhere they are made with Vanadium steel; and it is ridiculously slow to sharpen.
They are about 3x thicker than my similar Pfiel gouges. When I say thick, I mean there is a very large spine underneath the cutting edge running along the length of the gouge -- what is normally about 2mm between the shallow portion of the gouge and the complete bottom of the edge on Pfiel gouges is maybe 5mm.
What's the point of this? It is more metal so presumably more costly to manufacture. It makes sharpening take forever. It also seems like it is harder to use (but I may not be used to them yet) since the thick bottom portion of the gouge is getting in the way of the actual cutting edge!
Edit: I have added some pictures comparing the Pfiel to the Mifer.
Below the Mifer gouge is on the left. The bevels are approximately the same angle between the two but you can see how much longer it has to be on the Mifer.