As a SCH75 I have yet to see any SCH in my server actually use Klimaform very often. I've been using it very often lately and I've noticed a huge difference it makes. For example I'm able to land Slow on the Grauberg (S) Augment NM much more effectively with Klimaform and Sandstorm than without, and the difference is quite noticeable.
Also I've noticed that when I'm in areas with stacked weather, for example the Earth Weather with my Sandstorm, Slow is even more accurate. So I have an idea that Klimaform is in a way like the Elemental Obis, but rather than power to the spells, it gives the guaranteed added Magic Accuracy.
Any other input or theories on Klimaform would be most appreciated.