Another Laptop Question

My old man wants a new laptop now, as his was built in 1832…

Got the basic spec, but have found that if I add £80 worth of stuff, it will be eligable for a £50 discount… so was wondering, would upgrading the processor from:

Intel® Core™ 2 Duo Processor T6400 (2.0 GHz, 800 MHz FSB, 2 MB L2 Cache)

to

Intel® Core™ 2 Duo Processor P8600 (2.40Ghz, 3MB, 1066MHz)

on this system, make much difference?

Inspiron 15
Genuine Windows Vista® Home Premium SP1 – English
3072MB 800MHz Dual Channel DDR2 SDRAM [1×2048 + 1×1024]
15.6″ Widescreen WXGA CCFL (1366 x 768) TFT Display with TrueLifeâ„¢
Intel Integrated GMA 4500MHD
320 GB (5,400rpm) Serial ATA Hard Drive
DVD +/- RW Drive (read/write CD & DVD)
1 Year Limited Warranty – Collect & Return

Cheers