To the OP, yes. Several brands have been suggested, Fehrman is the only one that I have (of those suggestions), and I would rank it above Busse in quality and edge holding.
Let's talk about the warranty for a minute. For me, it's essentially worthless. The reason is, all of my Busse's I got in the early 2000's. I was new to the forum and bought in to the hype. None of the models I own are currently made anymore, so if I break one, I only get to apply the value of the knife to a newer model. I don't like the newer models, so I'm stuck. It might be a lifetime warranty, but if that knife isn't being made anymore, it does you no good if you want to stay with that style of knife.
The quality of the steel is good, but it's not head and shoulders better than anything else out there. Look at the claims in the same way that you would look at Cold Steel claims. The Carbon V Trailmaster was claimed to be better than 95% of the bowies on the market. Impossible to prove or disprove.
As for the standing offer to all the other makers, why would they care? That's like me having a standard offer to beat anyone on this forum with a 50 lb bench press. People just laugh and dismiss such a claim. If you want to see how INFI stacks up for edge holding, go check out Ankerson's thread. 1800'ish cuts on rope is child's play for plenty of modern steels that could probably beat that by a factor of 10.
Nothing. INFI is a good steel, but I've found 3V to be just as tough for my needs with better edge holding.
Or it's viewed as a little dog yipping at big dogs as they walk by. Busse had to get his start somehow, and since they are heavy duty knives, getting attention is almost always a good thing. CS did the same type of stuff with it's Trailmaster.
Back in 2004/2005 I had to get rid of some aspen trees, 3 30 footers. I dropped and bucked them, then use both a CS Trailmaster and a Busse Battle Mistress to limb them, just to satisfy my curiosity. The Busse held a better edge, but not by much. Maybe 3 - 5 extra passes on the stone for the TM to get caught up in sharpness. Both did well, but it wasn't a huge difference - except in price.