I don't think a single person on Earth could claim that WP7 was slow. Maybe those who never tried itI'm confused, are people saying that WP7 OS was slow with the single CPU?
I thought it was one of the fastest smartphone OS' I've ever used, even compared to the same gen competition.

The OP is claiming that WP8 is faster because of the dual-core CPU that WP7 phones didn't have, without taking into account that WP8 is a completely different kernel and that other factors have contributed to a "faster" UI experience.
It's all BS.