I have both knives and they are great but not similar. The esee is the quintessential woods knife. Good size, great heat treat and sharpens wonderfully easy. The only negative some people have is that the handle is a little small. I have med/large hands and I think it is fine.
The BM is a great tactical blade. You have to wrap the handle or custom make the handles. The knife is not uncomfortable unwrapped but handles help. The serrations on the back of the blade cut rope pretty well, however, they would probably get in the way of batoning.
Bottom line-if you want more military/ mall ninja ( and I don't mean that in a negative way!) go with the BM. If you will be spending more time in the woods than go with the esee 4.
TC