I own both.
I have 3 710's with a 4th pre-ordered.
I have a CF S90V Millie
I don't have a negative opinion about either and I carry each and love having each in my pocket. So I'll make some objective comments:
CF S90V Millie (my only reference):
$170 - $200
Awesome steel
It may break in but right now the closure detent is stiff. It takes a good amount of thumb push to break the initial detent when opening. But I can flip it open in one motion with some wrist whip.
LIGHT WEIGHT but strong feeling for the weight.
The carbon fiber scales are very grippy. But they can flex with strong twisting force.
A great knife for gloves too
Not notably easy to one hand close but doable. Not very suited well to ambidexterity
Can't fully disassemble the scales apart without damage to the lanyard hole area. The lanyard tube is pressed in or glued or something
Takes a VERY sharp edge but I haven't abused it so I can't comment of the edge holding.
Tip down only and only right hand clip. This means the lanyard will be in your pocket if you like a lanyard
The blade jimping is the best I have ever used. Grips like a banchee.
This is a very good knife and carrys so light and apt
710:
$100 - $120
I have a D2, two 154CM's and an M4 on preorder
Tip up right hand only clip
Rock solid knife. No flex or blade play. Feels very strong in hand too. Nice heft
The G10 scales could be grippier IMHO
The jimping could be deeper and grippier too
I tang end of the edge has a deeper recurve and makes sharpening near the tang end a little harder. Same for stropping. The thumb stud prevents the proper angle for stropping at the very tang end of the blade. It's doable though. The blade geometry is a better overall EDC because it is slimmer. It is easy to open envelopes and such with the narrow blade profile.
All the steels I have now sharpen scary sharp. The D2 is one of my sharpest knives next to the Bob Lum Chinese folder.
SMOOTH action! The Axis kicks ass. The final detent is sweet. Not too stiff and smooth as hell. The thumb stud is very easy to open the knife with. A simple flick with the right adjustment lays it open as fast as any AO knife.
The 710 seems to be able to handle twisting force more than the CF Millie
EXTREMELY suited to one handed open/close and truly ambidextrous!
A super good EDC and timeless classic that gives nothing up to any new design knife whatsoever
I think they are two different animals but both stand apart. As I said, I can't rate the G10 Millie so the price differential in my knives is huge.
I truly can't pick one over the other because I can carry either anytime I want. And I do
