Here is MY RX-C300 and GF-800z. Two of my favorite boxes (I use them WAAAAY More than my JVC-M90). They sit above my computer where I spend a lot of time. That these two gets the favorite seats in the house says something.
The GF-800z has better bass and twin cassette decks, and better sliders.
The RX-C300 is better looking, single cassette but has autoreverse and has Dolby and has spectrum analyzer. The sound also sound clearer to me, better mids.
The GF-800z is longer (as you can see in the pics). Because of the angle from which the phot was taken (I had to shoot up as these guys are high high up on the shelf) the GF looks almost as tall as the RX -- it's not. The RX-C300 is not as long as the GF but it's 30% taller. See photo below to get a better idea of shape. The design of the RX-C300 is not as busy, less silkscreening graphics and in my opinion, simply beautiful. More conventional shape. The GF-800z looks like a squat, long flat shape. Shape aside, it's simply an awesome boombox.
The GF-800z has better bass and twin cassette decks, and better sliders.
The RX-C300 is better looking, single cassette but has autoreverse and has Dolby and has spectrum analyzer. The sound also sound clearer to me, better mids.
The GF-800z is longer (as you can see in the pics). Because of the angle from which the phot was taken (I had to shoot up as these guys are high high up on the shelf) the GF looks almost as tall as the RX -- it's not. The RX-C300 is not as long as the GF but it's 30% taller. See photo below to get a better idea of shape. The design of the RX-C300 is not as busy, less silkscreening graphics and in my opinion, simply beautiful. More conventional shape. The GF-800z looks like a squat, long flat shape. Shape aside, it's simply an awesome boombox.
The Panny is fantastic looking with the spectrum analyzer 
love it .
