All I’ve used is the Minox and that was a long time ago, it is what it is for the price and it’ll get the job done. Personally I would give the Kowa a try, they are a quality optics company and the 40x would be nice if usable. Plus it only weighs 14oz.
If you get the Kowa post up your thoughts as others would be interested.
I bought the Celestron 56mm, looked through it once and couldn’t see 30 caliber holes in paper at 100yds with it and returned it immediately.
Leupold, Kowa, and the 11-33 Vortex Razor are on my list. Sold my Viper just because I didn’t feel like I actually used it enough, but now feel weird not having a spotter.