i owned a combo edge 806d2, and a 154cm 710. to be honest, even if i used the 154cm 710, the only time i would notice the difference between it and m2 would be during sharpening. and im pretty sure that it has a thin enough ground edge that i would barely notice it.
whith how i feel about knives now, the only reason i would take a combo edge 806d2 (or a plain edge to be honest) would be for the purpose of reselling it. the reason for this is how far your hand is away from the plain cutting edge. even on the regular plain edge, your index finger is about 3/4" away from the edge (i getting this from memory, i had the knife a good while ago so i could easily be wrong), and with the combo edge, its 1 1/2" away. d
for my practical theory of knives and their use, thats unnaceptable, unless it a large chopper.
the plain edge version of both of these knives make for good knives, but personally i cant own a knife with the 806 style handle anymore. it makes the knife bigger, and pushes the edge farther from your hand with little practical purpose (other bm's, as well as crk&t incorperate large hand gaurds without taking up so much space). its a big knife when it doesnt have to be. on the cuda maxx, you could use that thing for chopping, the 806 is pretty much dedicated to cutting tasks.
i also like the blade shape of the 710 better, but thats a personal preference to slight recurves. as far as the thumbstud vs. opening hole, i would go with the thumbstud, because i can open the knife with very little effort, and very little hand movement, where as with the opening hole i had to work at it.
while the axis lock affords you nearly effortless opening regardless of what opening method is on the blade, i found the thumbstud on the 710 to be preferable to pulling the lock back (effectively making it a gravity knife), because it made it like a switchblade. slight push upward (no rotation or diagnal direction), and the blade would swing open from any position will a fair amount of speed.
if i didnt need the money for other things, and wasnt carrying fixed blades exclusively (not including the leatherman - thats pliers
(so i keep tellingmyself... considering i use the knives on it more then any other knife ive ever carried), i would have never sold it (710).
both will cut well and make for very good edc knives, but everything i have come to beleive makes a good knife points me in the direction of the 710