I haven't adequately compared anything to Schmidt but it really depends on what mag range you're using to compare them. According to ILya's review of the k318i next to a TT315M it's extremely good not quite TT but not far off, Bill also tends to like the k318i more than his S&B ultra shorts. Of course different optics yes, but there isn't much difference optically between the K318i and K525i at all that i've seen having owned both now for over 6 months. Max mag? Yes Kahles falls behind with the k525i it loses some on the top end, it isn't up for debate. Through the magnification range, say 5-20? For the brief comparison i had with the ZP5 it was pretty equal FOV and CA control withstanding. I've only been behind one PMII so as i said i can't really speak for that optic but everything else outside of TT & ZCO i've had some time behind and the k525i in terms of resolution and contrast a little below max mag is phenomenal, it just comes at a cost that most aren't willing to put up with, I.E. very small FOV and shallow DOF. It's a hindrance on what could've been a home run for Kahles IMHO.
Beating a dead horse but at the end of the day every piece of glass in this price range is good enough. There are opinions about them all with most lining up like this, TT residing on top with Hendsoldt, then Minox/S&B/ZCO/Kahles etc. I still recommend getting behind them all, shooting them all if applicable, and seeing first hand what reticle you like the best. For me it's the SKMR3 and i think if i had my pick currently the Mil-XT would be my second favorite until we inevitably get a SKMR4. MPCT2 is up there as well i just love the alternating 2/10th vertical of the Mil-XT, it's something that sticks out to my eyes as to never get lost or mix up a hold. Which i did with the H59 on a boat stage last year out of my mark 5. Of course practice behind any system alleviates this, but simultaneously if i can make it simpler i choose to do so.
