Is Lenovo Z580 good to buy?

Dear Friends
I want to buy a lenovo Z580 laptop but there are 2 different types of it as below, would you please help me to choose the best one? With reasonable price.

1-http://www.saveonlaptops.co.uk/LENOVO-Z580-M81KHUK_1336878.html

Intel® Core™ i7-3632QM Quad Core (2.2 GHz, Intel Ivy Bridge Architecture, 6 MB L3 cache, Features Intel Turbo Boost up to 3.2GHz)
Graphics: Dedicated (NVIDIA® GeForce® GT 635M with 2GB DDR Dedicated Memory)
hard: 1TB
679GBP

2- http://www.saveonlaptops.co.uk/LENOVO-Z580-M81J3UK_1296623.html

Intel® Core™ i7-3520M Dual Core (2.9 GHz, Intel Ivy Bridge Architecture, 6 4B L3 cache, Features Intel Turbo Boost up to 3.6GHz)
Graphics Integrated (Intel® HD 4000 Graphics with 128MB Memory)
HARD:750GB
599GBP

Why the second one is dual core but it is up to 3.6GHZ which is higher than the first one?

Here is one of the blog I found helpful to go for Lenovo ideapad.

http://lenovo-ideapad-z580.blogspot.com/

let me know if it helps you.

You can go ahead with 1st option
as it has latest processor