The quintet is an over the top romantic behemoth, even in a comparably lean and straight recording such as Heifetz and friends. I am not a frequent concertgoer (combination of financial and geographical reasons) but I have heard the Franck quintet in concert and it is a huge wallowing sound experience (I was surprised how the ensemble that sounded lean and smallish in the Ravel quartet could become so big in the Franck, Q Modiglinani, forgot the pianist). They played the andante from the Brahms quintet as encore and after the Franck it sounded like Haydn...

So whereas I basically loved the violin sonate since my first recording (might have had a tape before) which was Oistrakh/Richter on Vox (orig. Melodiya) I was also not immediately equally fond of the quintet.
As for the quartet, I am still not entirely convinced. It is also huge (on a scale with late Beethoven and Schubert) but not as attractive for me as the quintet, which bothers me a bit as I think it is a piece I should like more than I actually do

I don't remember the sound issues with the eloquence but I have to check. I have three recordings, the Fitzwilliam, the Petersen and the one from the La Monnaie box. tbh I don't remember much about the last one as I had bought this mainly for the pieces I had not already in other recordings. The Petersen might be a bit too much on the lean side for such a a late romantic piece. I think there is a historical recording by the Loewenguth Quartet (but maybe I am wrong and they only did the quintet). The quintet is so much better covered on disc, the quartet does not seem a favorite with ensembles (even less than Bruckner's quintet, a not dissimilar piece).