Ritek G04 media isn't bad when you get the good ones... not too great when you get the bad ones. However, G04 is getting harder and harder to find since the M02 has replaced it for the most part now. I don't think any more G04 discs have been made in quite some time. However, I've received multiple contradictory reports from various people within Ritek on that...
Personally, I haven't been impressed with most of Ritek's 8x media.... but some people seem to love it.
Punch Cards -> Paper Tape -> Tape Drive -> 8" Floppy Diskette -> 5 1/4" Floppy Diskette -> 3 1/2" "Flippy" Diskette -> CD-R -> DVD±R -> BD-R
The Progression of Computer Media