Well, I used an Imperial blade today that Dave Reinhold had given me. It had a golden end at the teeth so I'm guessing it's a titanium nitride coating. Anyway, I was only using it to cut 3/4" particle board along a short wall and along a bathroom marble saddle. It cut along the saddle just Fein [big grin] and started on the wall area, cutting down 3/4" along the wall edge so the particle board could be ripped out. The blade started bending on me up at the attachment point where it meets the blade mount and my cut started going off so I had to shut down the Multimaster to bend the blade straight again. Got a little more out of it and it snapped.
Never had an expensive Fein blade do that - never bent on me or snapped on me.
I'm guessing that it's not just about the teeth. There's also a difference in the metal and maybe some heat treatment that Fein does and Imperial doesn't.