You're right that Nas' hype wasn't to the degree of Snoop's. But hearing from East Coast heads, specifically those from NYC, illmatic was a big damn deal.

Granted Nas' hype couldn't have been higher than Snoop's because Nas' 'debut' basically one hype verse on a song that never charted while Snoop got everyone's attention on Deep Cover, which was a single and also featured on a soundtrack, and then took his MC'ing to another level on The Chronic. But Illmatic's quality definitely lived up to the hype in a similar way that Doggystyle did.