My buddy is running the Mountain and has been extremely pleased. His criteria going in was lightest weight option possible without sacrificing durability- says it checks both boxes solidly.
Another H1000 fan here. Has been more consistent for me but not as fast as N560 w/ 175 Berger EH, 175 Eld-x and 180 Eld-m in my 7 PRC. Still pushing each to about 2900 fps, with low single digit ES's in best loads.
Did a 260AI on a Rem 700 w/ DBM that feed fine and shot lights out. I would think the Tikka mag design might feed even better than the staggered Rem mag box, but no first hand experience.
Came off of a Kuiu Ultra 4000 and the K4 3600 definitely handles weights >50lbs better the Kuiu. Everything just feels more durable than the Kuiu. Perfect 1-4 day pack for me.
I’d echo your take regarding optical performance vs EL Ranges I owned previously. That said, definitely a solidly built bino, with best in class ranging capability/feature set. No regrets making the switch.