A favorite topic on mine. I use a variety of wedges, lately mostly Madsen's blue wedge which is made by Piller, the same people who make Double Taper. I also have some Double Taper, K&H, Black Bear, HardHead (both types), and some green Bailey's.
The Black Bear have a very small head that is easily damaged so I would not buy them again even though in very small trees they do stay in the cut better than any other wedge I've used. The green Bailey's is too mushy and even though they are soft pieces break off. The HardHead means you have to be wearing safety glasses and of course they are heavy but for problem trees the big HardHeads can't be beat. They just have to live in the truck tool box rather than in my pouch.
All the rest have never given me problems. I prefer texturing on both sides vs one side smooth. A few days ago I bought 2 eight inch barbed wedges who's name escapes me right now. I like trying different things like wedges to see how they work. The barbs may be a gimmick but then again maybe not.
My normal wedge driver is a 4lb single bit axe designed for falling (rafting) and has a polished poll. It is made by Council and sold by Madsen's. Mine has a 28" helve and fits upside down in an aluminum scabbard which sits at the small of my back. The length of the helve is personal and since I'm just over 5'8" 28" fits me well. One of my bar scabbards for a 24/25" bar holds a boy's axe, a 2 1/4lb head with 28" fawns foot helve so on occasion that axe is my wedge driver. It is my least favorite driver. Finally at times a carry a miner's axe which has a 3 1/2 lb head on an 18" helve. This combo works very well especially when falling one tree of a tight grove where a longer handle is clumsy. I've never felt the need for a slegde hammer though at times a 36" helve would be nice.
One of my jobs is falling snags in the Sierras and sometimes in the SF Bay area. The bigger snags, say 48" DBH and larger can use lots of wedges to push over. I carry more wedges in my truck tool box than some saw shops have in inventory. Being a gear geek just makes it worse. However I've also been cutting wedges out of fir limbs by truck headlights when I ran out of wedges. This particular dead fir was sky bound and I had to darn near push it to the ground. But, I didn't leave it!
To answer the original poster, yes K&H are top quality. If that was all I could ever use that would suit me just fine.