I have never actually seen or handled a Montana rifle, so take this for what it is worth.
Some rave about them. I'm sure that they can be fine. However, it is my understanding that the actions are cast, using the lost wax method. Aside from the claimed strength of forged steel actions and unlikelihood of flaws that might exist in a casting, about which some gunmakers are vehement, equivalent strength would have to come from bulkier actions using more steel. I would guess that the added weight (or less strength, if the same size) would be a disadvantage.
I have several Model 70s made in different eras. They all balance beautifully in my hands, even the heavy post-64 push feed .458 Win Mag, compared to most other bolt actions I know or own. I am very sold on them.
I realize that Montana says its CRF bolt action design adds a couple of improvements. However, unlike one major competitor, I have never heard of any Winchester products having safety-related design flaws. For me, they are the best. And most of them are quite beautiful, even the simple standard 70s with plain wood.
