Great stuff for mid-priced production knives. Holds an edge very well. Benchmade's heat treat offers good toughness for M-2. My concern over time was whether the edge would fade without use due to corrosion from body moisture, but I haven't noticed any tendency like that at all.
I would rank Benchmade's M-2 much better than their ATS-34, even with BG-42 but for corrosion resistance, and almost even with Spyderco's CPM440V. CPM440V should have better edge holding and stain resistance, but the Benchmade M-2 is tougher and serves well with BT2 coating.