Both are marvelous speakers.I recently purchased the 601's but returned them and replaced them with the 602's. I bought them for rear speakers and occassional stereo listening. The 602's take a bit more power, and have a deeper low end. For main speakers I'd recommend the 602's.
I have the 601's for surrounds and wish i would have gotten 602's. 01's are fine for movies but for multi-channel audio,one size up would have been nice.