I'll offer up what I've read about the CZ and Kimber. Note again this is what I've read and not what I know from personal experience. I put it here only to suggest you research it yourself further.
From what I've read, those who own a Montana either love them or hate them, not much in between. I would say that of those who hate them, the complaint seems to be bad quality control followed by poor customer service.
Also from what I've read, CZ has experienced issues with rifles shooting so low, scopes cannot be adjusted far enough to even get close to achieving a proper zero. This issue seems to not be that limited. Where I read that, a number of similar complaints were posted. Now in fairness to CZ the issue was remedied after sending the rifles back for service under warranty.
Again I encourage you to research these issues for yourself.
Now for what I know concerning my M70 in .375H&H. This is my first DG rifle and I have all of about 8 months experience with it.
The good: I like the weight of it and it really helps eating up recoil. Thanks to another member here, I have a very accurate load in 300gr A-Frames. I have a nearly as accurate load in 300gr TSX. If I ever miss my spot while hunting with it, it won't be the gun's fault. I won't be bedding this gun or floating the barrel. The price is still quite reasonable. Personally I like the looks of the gun. It's a dull finish on both the stock and metallic parts. Shiny while pretty is not something I prefer in a hunting rifle.
The bad: With handloads I ran into a feeding issue. It was a problem with the front edge of the brass at the neck hanging up on the rear face of the chamber. The solution thus far has been to crimp my rounds as suggested by the gunsmith. Since doing this, I haven't had an issue. However, I want to go through another 50 rounds before I totally declare victory. If I even get one more, I'll be sending the gun to the gunsmith to resolve this. I think it's a small issue to resolve, with bascially just rounding off the edge a little on the chamber face. Should I have to do this with a brand new gun? Probably not, but I've not read this to be a common issue. While I do like the trigger overall, mine is set a bit heavy. I don't know that this should be listed as a bad thing but I probably will have it lightened a little bit.