I think what he meant is, when it came out did it have a similar impact.
To answer the question, the 9800 was the fastest card you could get at the time. Multicard setups didn't exist then and we were all on AGP. That, with a 2.4ghz Athlon XP and 1gig of ram was a dream machine. The 9800pro was the best of the best. Nidia's competing cards, the FX5xxx cards were crap. They used dual slot coolers, cost more and the FX5800ultra was famously noisy. The Radeon 9 series also shares something with ATIs current cards, uber AA performance. Before then AA and AF were features that you could really only enable by sacrificing other graphics aspects, with the 9800 you could turn them on with no performance penalty. It was so good at it and the Nvidia cards so bad at it that in some games the 9800 was literally twice as fast as the competition. You don't see those kind of numbers anymore.