I'd have to re-listen to the Caspar da Salo but they are rather slow in the first two movements of this piece but in a relaxed, "genial" way I find appealing for this quartet and they are, IRRC bouncy and funny in the Scherzando (and skip most repeats there, so that it lasts only about 4 min.)
It's an unassuming but interesting quartet. The first movement has basically a second development section in the recap/coda with comparably remote (A flat, I think) modulations and a little fugato.
I once looked at the tempi of different recordings and it seemed possible to take quarter(1)=quarter(2)=eighth note(3) ~140 bpm for the first three movements although this might exaggerate the lack of contrast. According to my notes the Caspar da Salo play ca. 130, 144, 152, i.e. they get faster in each movement whereas Festetics have ca. 144, 132, 132. (I didn't have the Mosaiques back then.)