There are various views of Schimmel, I almost bought a new one a couple of decades ago. I am German, live in the U.S., and can give you the education I went through with Schimmel.
Larry Fine gives Schimmel a very high rating, and out of the box the quality overall really is quite high. So here in the U.S. they are sold as high-end hand made German instruments.
I went to a dealership in Germany that sold many brands, including new Bösendorfers, and the owner of the shop (which was also a piano factory, very well know in Germany, but I won't mention the name) said of his large Schimmel "well, at least they give it an aftertune."
Schimmels are NOT hand made - they are Germany's most mass-produced piano. You will not see a Schimmel on a concert stage. They are, though, at a very high standard for a mass produced piano. In this sense the quality is quite high. They are really Germany's Yamaha, and indeed, Yamaha has been involved in the company.
Also, even in mass produced pianos, you can have sudden gems. So if you find a Schimmel you really like - no, you are not buying a Bechstein, or a Blüthner, or a Bösendorfer, but you might be buying a very good piano that will hold up.