Looks like you already got the info you needed. If anyone else is interested, I had the FS 110 for several years. It was great on grass and small brush (three point blade) , but just wasn't up to doing small trees with a cutting blade. I've had a Stihl FS 460 with a carbide blade for about 3 years. It's a tree eating machine. Will cut up to 2" on one pass, 3+" with several hits.
I tried all the Stihl blades. The scratcher works as well as any on trees, but only lasts about 4 hrs of continuous cutting (sandy/rocky soil). The after market carbide blade is on it's 6th full day of use and is still going strong (though missing a couple of teeth). As I recall, the carbide blade was nearly the same price as the scratcher. Search for carbide brush cutter blades. I've seen posts elsewhere that talk about using a carbide circular saw blade. Please don't do that as they aren't designed for the speeds or impacts of a brush cutter.
I used a blade on a loop handle while I was figuring things out, but I won't ever do it again. It was just too easy to slip, trip, or slide a foot into that blade or recoil the blade into me. With a handlebar and harness there's much less fatigue and it's extremely difficult to get any part of my body near those spinning carbide teeth.
I also experienced performance/maintenance issues when ethanol came on the scene. I will not use ethanol gas in my small engines. I have another post here praising my Stihl tools - I have no interst in Stihl (or carbide blades) other than a very satisfied customer sharing good experience. I wish I'd found these forums years ago.
