They look like a well built piece. Certainly wouldn't have any issues with restricting ejection as some other mounts do. Also, the higher mount, allows for lower rings which have a savings in both weight and bulk.
As long as the wear points have been 'hardened', it should last a lifetime of abuse.
I have never understood why there is such an adversion to high strength Alum alloy in tactical rifles. There are many many alloys of varying properties and some much stronger/resiliant then common versions of steel. There is a weight savings using alum too.
The aircraft and racing car industry has come up with amazing alloys and basically don't use much steel. Nope, NASCAR is about as modern as a model T in the racing world. There is a lot of alloys used there too - if they get away with it.
Then there is the question of scope tubes. Are they any scopes manf today that don't use an aircraft type alum alloy to make the scope tube?
Seems to be strong enough...Let's not condem something until it has earned that claim.
Jerry