If you haven’t visited any rococo churches, stop,at the Wies church
On the other hand, if you have visited any rococo churches, don't bother with Wieskirche. It's just one more over-the-top, gaudy church.
In 2007, I started my Romantic Road tour in Oberammergau. I know, it's not really on "the Road"; Füssen is the southern terminus of the Road, but I had already been to Füssen three times, so I spent the night in Oberammergau and took the bus in the morning to Wieskirche to start my journey on the Road.
I had an hour between buses at Wieskirche. I arrived at Wieskirche, took one look inside and said, "yeah, it's one more rococo church."
After a couple of minutes, I went across the road to a gasthof for lunch.
On that trip, I stopped at two rococo churches, Wieskirche and the chapel at Andechs. I have postcards from both, and I can't tell which is which without looking at the descriptions on the back of the cards.