You have the same setup as I do (Neo and Note 5). I've had the Gear 2 Neo for over a year now and how I "thought" I'd use it became a bit different from how I do use it. I do like it and have debated like crazy getting a Gear S2. For me, if I didn't have the Neo already, I'd jump on the Gear S2. But like you, I already have a solid smartwatch. And truthfully, the one thing that keeps me from getting the Gear S2 is the lack of a speakerphone. So in comes the 3G version and it solves that. But I have an old unlimited data plan with Verizon so I can't add any new lines. So what I might do (I'm also still in debate) is get the 3G version on my friend's plan, then cancel the plan but keep the watch. I'm pretty sure you can do that. Then I won't have the 3G ability but I'll still have the ability to take and make calls over BT which is what we do already with the Neo. So that's what I'd recommend you do as well since it appears you too value the ability to make/receive calls. It's definitely a feature that went from "eh, who needs that" before I got the Neo, to "must-have" for me after having a smartwatch with that capability for a year.
FWIW, I might hold off still in the hopes they come out with a 3G version of the Classic watch. Then I'd jump on it. Who knows if that will ever come, but until then I guess I have a really good smart watch that's a little less stylish and doesn't have nearly the polished UI that the Gear S2 has.