Ghz does not always relate to speed
I believe that some here are a bit confused when it comes the speed of a computer. The rates CPU GHz is not a accurate indicator of overall speed.
There are many factors that affect speed:
1) Processor Architecture (number of cores etc)
2) Processor speed
3) Bus speed
4) Amount of memory, type of memory and speed of memory
5) Graphics
6) Hard drive formatting, speed and type (ssd vs sata etc)
7) 32 vs 63 bit OS
8) The chip set being used
The point here is that any one component can slow down all of the others. Overall hardware speed relies on how well entire architecture performs, and where the weakest link is.
You think that just because the Latitude z600 uses a SU9400 @ 1.40GHz,(or SU9600 @ 1.60GHz) processor that it is slower than a 2.0 + GHz machine? Think again.
Check out these PCMark benchmark scores:
Lenovo ThinkPad X301
Intel Core 2 Duo SU9400 @ 1.40GHz, Intel 4500MHD
4,457 PCMarks
Apple MacBook Air
1.6GHz Intel Core 2 Duo P7500, Intel X3100
2,478 PCMarks
Apple MacBook Pro 13
2.26GHz Intel P8400, Nvidia 9400M
4,136 PCMark
It look like the 1.4 GHz Lenovo X301 outperforms the 2.26GHz MacBook Pro 13".
I own a MacPro with 16GB memory (for work), a 15" MacBook Pro and a 1 year old iMac for home, I love my mac's. I just think they need to be pushed like any other company to continually innovate. I like the z600. It has a lot of very innovative features that I would like to see in a future MacBook Pro.