Well what db says is correct, essentially. In that despite noticeable wear/scratches etc to the BT2 finish after use, a sufficient amount of it will remain on the steel to continue to do its job - corrosion resistance and enhanced cutting smoothness (arguably). Even after significant, prolonged use. In other words, what the eye sees is misleading in a sense - the coating is still there.
If you want to know more about this, take a look here -
http://zvis.com/knives/folding/bm710ax.shtml
There are some photos and other links there of interest, including a prior thread here.
All that said though, I like many do not find the BT2 finish appealing, for a number of reasons (see what Joe Talmadge has to say about it in the thread I refer to for example). For one thing, I don't like the visual appearance after use, despite the coating still being effective, or even before any use at all for that matter.
I will always prefer a plain steel, uncoated blade. But for steels with high corrosion concerns like M2, it is pretty much certain that BM will only offer them coated - either BT2 or BC1 presently. Ideally, you'd have a choice, in which case mine would be the latter for sure. For reasons of production economics or whatever, however, that isn't the way it is.
The last Forum Knife BM produced was a 705 with M2 steel and BC1 coating. A really great knife. Also, you could say it indicates that quite a few BM Axis lovers have the same preferences in relation to all this.
