MacBook Pro 15" Screen Quality

Hi

I have been reading reviews over the net on MacBook Pro 15" unibody models, with 3 different CPUS all with the same 6mb cache and 512gfx.

- 2.53
- 2.66
- 2.8

Each review shows a difference in the screen quality, such as illumination and contrast ratio.

NoteBookCheck would rate the 2.53 and 2.66 models (6mb cache types / 512gfx) better for illumination and contrast than the newer 2.8?

I am a designer, i would buy a second hand MBP is the screen was better on the older models than the newer ones?

Help please?

here are the review links, you'll see the top one seems to be the best for screen quality with more or less 1000:1 contrast.

Notebookcheck: Review Update Apple MacBook Pro 5.1 (Unibody, 9600M GT + 9400M)

Notebookcheck: Review Apple MacBook Pro 15" v5 2008 (Unibody, 9600M GT + 9400M)

Notebookcheck: Review Apple MacBook Pro 15 Mid 2009 2.8 GHz