I just got a Horizon Perfekt, I second the recommendation to get the horizon straight, I just shot my first roll today, and I found it quite tricky to get everything straight.
Also I guess keep an eye on the light, there is no meter in the Perfekt, and I assume the 202 as well. Maybe get some Portra 400, it's very tolerant of under exposure, which might be good if a lot of the wedding is conducted indoors.
I guess just get used to holding it steady and straight, and practice loading too, my first roll took me a while.
First impressions are that it's a beautiful camera, I like the unusual design, and the fact it does something completely different to 99.999% of cameras. I think even with curved horizons and the other peculiarities of the shots you'll get out of the 202, you'll be able to present photos *a lot* different to the usual DSLR stuff.
Best of luck shooting the wedding.