Benchmade seems to put the same grind -- a flat sabre grind -- on all their knives. So the grind itself doesn't give any particular advantage from one to the other, although some knives do seem to have slightly higher grinds. Since the knives don't distinguish themselves by grind, you need to look at other factors: blade shape, handle, and steel.
On blade shape, obviously different shapes work better for different things. Generally speaking, a recurved blade excels at slicing, more than a non-recurved blade. That would favor the Axis 710. The AFCK's forward rake, while not as effective as a recurve, does enhance slicing ability.
The shape of the handle, how well it fits your particular hand, and well it's mated to the blade, also can significantly effect how a knife cuts. I don't think any of Benchmade's handles are particularly bad, in fact, by and large BM's handles all work very well for me. I feel the AFCK/TSEK handles are the ones that most improve cutting performance for me, in everything from light cutting to hard defensive-style cutting. The handles of the Ares, 710, various Pardue models, etc., all work very well for me, too.
For blade steel, for pure cutting ability, blade steel only becomes a really important factor if you take advantage of it in your sharpening plan. If you have two identical knives of 420HC and S30V, if sharpened at the same angle and grit, will all make one cut with about the same performance. Obviously, as you continue cutting, S30V's superior wear resistance, strength, etc. will pull away. But to really get the best out of a higher-end steel, you would take advantage of S30V's greater strength and toughness and sharpen it at a lower angle. Keeping with that same theme, I believe the M-2 and D-2 bladed knives will cut better, if you take advantage of those steels in your sharpening plan (that is, make the angle lower than you would with your 154-CM knives). That means 710 or Axis AFCK.
Putting it all together, I'd say the 710 will give you best pure cutting performance.
Joe
