Man what a throwback, memories I forgot I had. I was all about upgrading my K6-2 450 to a 550, but was equally fun to cheer on AMD's Slot A chips that had begun to erase Intel's dominance at the time.
I really followed computer evolution during the GHz wars. Watching a CPU go from 300Mhz being fast to 2GHz being fast was amazing. Then watching as AMD pulled 1.8GHz parts and kicked the pants off of Intel's 2.5GHz parts was equally incredible to young me.
Now I see generation to generation pushing 5->10% improvements and mostly go "meh".
Those lower-clocked Durons you mentioned were fantastic value though - I remember buying a 700 MHz part and running it at 900 MHz (after using a pencil to short those traces on the chip that let you manipulate the clock multiplier)