In my opinion the NPZ
universal AK mount and the SVD variation have been the
best mounts I've seen to date, especially when
compared to the older and more common BP02 that most
of us have seen at one time or another. These days a
new Russian made competitor from the Tula factory has
arrived which is the Alpha mount. While I didn't think
the NPZ could really be improved on other than weight,
the Alpha does have a couple features that the NPZ
Top: NPZ AK Universal
Bottom: Alpha K1958 AK Universal
To me the biggest indicator of quality in a mount
is the locking mechanism. The NPZ mount uses the
traditional military locking mechanism that is found
on all of the military issue optics like 1PN34,
Rakurs, Kashtan and others. In my opinion this
continues to be the best mechanism available, but
other types are effective as well.
The Alpha uses a variation of the NPZ mount which I suspect is probably less expensive to manufacture. I feel that it will hold zero just as effectively and is tightened the same way as all the throw lever versions.
Weight for the Alpha is 9.1oz vs 10.3 of the NPZ. While both rails have a center channel to allow the use of irons, the NPZ sits slightly to the left and makes seeing the center post a bit of a face cram into the stock to get a decent site picture. The Alpha is perfectly centered on Russian AK's and is much easier to see the iron sites clearly.
Both NPZ and Alpha will mount to AKs however the NPZ will block the AK irons due to being slightly higher. I think the Alpha is a fantastic mount but it has become ultra rare and I have not seen any examples for sale since 2013 or so
The NPZ mount comes in AK and SVD height. Both versions will mount correctly to the SVD rail but the SVD version is too low to mount to the AK. These used to be super rare and very expensive but now in 2016 they seem to be a little more common and prices have come down
AK mount (Top), SVD mount (Bottom)
Example of SVD mount on Tiger with PSU1-4