Nothing we haven't heard elsewhere - but I am curious about the first movement of the Sextet in C being 4 minutes longer than the CPO recording...
https://www.hyperion-records.co.uk/dc.asp?dc=D_CDA68380
Maybe a repeat not taken by the cpo players?
Just listened to the CPO recording - and that could well be it. A repeat would be good in this movement as the thematic material is none too distinguished, the tonal plan is quite ambitious, and Ries has a tendency to develop themes immediately - all of which obscures the structure. It can just sound like a mass of enthusiastic playing. And I say that as a big Ries fan, but this piece has never really impressed me much.
There is a repeat in the first movement on p.7 of the piano part. The opening tempo is specified ("Maelzel's metronome quarter=152) as is the metronome at the beginning of the variations second movement (but some other tempi are only given in more general terms, including that of the brief Adagio preceding the Allegro quarter=112 finale, but longer sections too :), and of course ensembles ignore even precise metronome markings all the time...
Thank you for that detail.
I suspect more adherence to the score, and care over expressing the structure, would have helped the CPO performance.