Hello, and welcome to the latest in my semi-regular "This classic lo-fi album is better than that classic lo-fi album by the same band" series.
Propeller - musically more inventive. Crunchier. More emotional resonance. Perhaps less distinctive pop melodies, but better songs overall. In retrospect, I think Bee Thousand is a fairly good indicator of the direction Guided by Voices were eventually going to head in. Which is a bad thing.
Also, for anyone thinking otherwise: Alien Lanes has no place in this thread.