What camp are you in? Control round or push feed? I have both and in my book all things are moot comparing the two but you get the most tongue noise from CRF guys.
While I have never experienced it, I have talked to those who claim to have had a lever gun bind / jam due to glacier silt in the action. I have 94 30.30win that has worked flawless but due to its birthday, its a safe queen.
Break open is reliable is all conditions, I know those with single and side by sides. Personally do not own but those who use side by side on dangerous bears think they are tier one but $8k+ and $400 for 20 rounds is a little steep for most.
Semi I would not hunt dangerous bears and in deep arctic cold they can become unreliable. I prefer a Garrand action Vs Stoner but again, its Ford Vs Chevy just Garrand in my experience is more reliable in all conditions and only with a backup would I pursue bears in deep thicket.
I am not sure what a top tier rifle is especially to a single person. For me, its something I can tote mile after mile, up and down thousands of feet of scree, dry wet icy snowy, get drug through alder thickets, get dowsed in glacier creek, wallow the swamp kegs, dropped and kicked, and allow me to put the copper and lead pill in the kill box. While many may consider it not top tier and others may dismiss it as beauty queen, my Wby Mark V light weight hunter in 340wby with Leupold Alaskan 3x scope has done all this. Three Wbys in total for me. Its a wood stock blued barrel that has never a spot of rust even coastal and boat hunting. A long time ago I aligned up the cross hair as a monster book brownie and squeezed the trigger and nothing happened. Its the only time it failed but I did not push the safety hard enough so it was my fault starring at massive brown at 80-90 yards as the boar ripped into shrubs looking for grubs, he turned and starred directly at me seconds before I flicked the switch and I was sweating to oldies in 15f and well did not do my part and when I did flick it starring me down, he spooked and turned the pencil disappearing into the thicket. The only time I had the chance at a book bear.
I also prefer Tikka T3 SS as tier one, For me, no need for a $2000-$5000 rifle to hunt with, what is the extra coin giving me over my Wby and Tikka. I will take that money saved and use it for bush flights or food and supplies for my next hunt or even better, ammo to hone my trigger skills.
Granted we all love to talk guns and ammo, $5000 lazer beam or $500 Tikka, 243 or 338, SMK or Partition, the only sum of the equation is the trigger actuator,