You lived in Tokyo yet never met a woman who used すげえ? Google "ギャル" you might find something. Anyway, I don't live in the Kansai region so I don't know what kind of dialect you or the people around you use, but over where I live the "~ええ form" is normal. The way I see it, すげえ is like calling a kid a ガキ. It's just how people learned their way of speaking Japanese, whether it's how their parents spoke or how they used to talk with their friends. Nothing wrong, nothing right.
BTW, "すげい" was a typo, lol.
Oh yeah, thanks for the code Kaoko .