Exactly as said above, I've had and have both, the AI mount while appearing a bit crap in relation to the rifles themselves, works fine, no problems. However, once you've had the SPUHR mount, you wouldn't go back,
the built in level, the wedge to level it & the possibility to add a small pic rail make it a no brainer.
It's more expensive than the AI mount but it is far better made. The two AI mounts are in a drawer and the SPUHR mounts are on the rifles...