It's a love hate thing and very individual. For me the SNG fits my hand more comfortably, but I don't like the loss of cutting edge. The SMF has the blade size I'd like but the handle does not fit me well at all. I'd also say to me the CC models are much more comfortable than the square edge non-cc versions, and much less obtrusive in the pocket. I will say that either one feels better in the hand than you'd think by how the handle shape looks. In the end I rarely need to choke way up on a knife so I didn't like the loss of blade length, to me spyderco with say the manix 2 does a lot better job of still doing a two hand position but with minimal loss of blade length. My SMF is only about 1/4" longer than my manix 2 if you compare edge to edge but it has to be at least an inch longer overall.
Of all my folders I'd say my ZT 560 is one of the most comfortable in the hand long term, and I'd say for my hand spyderco does the best job overall of ergonomics across various models. They just don't up or down size knives they consider the ergonomics for example both the Manix 2 and Manix XL are equally comfortable in my average size hand while they each have much different handle sizes, most companies would just scale everything up/down equally and be happy with that, spyderco obviously put some effort into upsizing the knife but keeping the ergonomics.
I think people would be really surprised if they put all their knives out and started handling them with their eyes closed paying only attention to how well the handle feels in their hand. For me a lot of very expensive knives have worse ergonomics than many production knives. For example I love my CRK knives for their fit/finish, but neither my Zan or my 25 is that comfortable in the hand long term compared to say a PM2, Manix 2, or 560.