I think you could do alot better for the money. Even though Sony's screens are excellent the components in that laptop are not that good and certainly not worth the £631(0nline price) and £700 (in-store price).
Why not choose a Acer laptop, I have one and the screen quality is very good.
ACER ASPIRE 1642WLMI (£579.99 online and £600 in-store)
Excellent spec for the price and would handle alot more than the Sony vaio with a Celeron M Processor.
Here it is to have a look click here