I personally think the statement of reducing fatigue to allow you to ride longer and stronger is just marketing hype. I also think the Auto mechanism which is advertised to save time strapping in is also marketing hype because in order to strap in properly you need to do a few extra steps which pretty much negates having one less strap to mess with.
From the above it may seem like I'm not happy with my Auto Evers but in reality I couldn't be happier. If you're looking for a super light, stiff and responsive binding you can't go wrong with these.
I'm 36 btw so not too far in age difference. I pretty much do the same thing you're doing to get in shape and besides the effects of altitude I usually don't have any problems with fatigue