Billy Goat
WKR
To me, it doesn't seem as if these replaceable blade heads are as sharp as they used to be. Maybe it's a liability issue, I don't know. But when I was hitting it hard in the late 90's, early 2000's, I was almost afraid to swap blades in my Muzzy heads--they were like scalpels. I cut myself more than once.
Late response, but....
Company that use to make blades for wasp, muzzy, and many others was just a few miles from me.
Guess what, got bought out, moved much of the production to China.
I haven't really investigated it, I have a neighbor who was an engineer pre and post buyout, but I suspect it's just quality of material. Initial blade sharpness is one thing, edge retention is another. I think it's in the retention many of the new replaceable blade stuff suffers.