Sure his middle and late quartets are more proto-romantic. However what rule of god there to say that proto-romantic >> Classical style? As someone who thinks Mozart and Haydn are both top 3 composers of all time, I don't really see his Beethoven early works that model on their style to be mere stepping stones to his later work but great works in their own right especially since even in his early works, there is already idiosyncratic style that is unmistakenly Beethoven with his rhythmic drive/excitement and dramatic contrast.
Beethoven works in the classical style is of the highest order that are of equal or better quality as works by Haydn/mozart.
In terms of recordings
I prefer Emerson String Quartet for the vast majority of String Quartets although I'll pick Takacs for String Quartet No. 9, Lindsay String Quartet for No. 13, Eroica String Quartet for No. 10, 11.
I like Emerson performances for emphasising the rhythmic drive and "rock and roll" like energy of his work.
I can't listen to performance of String Quartet No. 6 and hear plodding slow tempo after hearing emerson string quartet performing it.