Just got these as well -- affordable/ish and well-packed courtesy of The Bastards.
I think the sound and presentation is really good. The sessions themselves are hit or miss, which is how I always felt about the Sextet's 1970s LPs as-issued. The Sextet session with John Surman as a guest, which didn't make it onto these LPs*, is choice. And of course Kleinschuster and Pauer were part of a brilliant NDR Surman session from '69 too.
* google it, it's out in the ether