The HP I'm talking also had a 512mb dedicated 9200m gs so the only difference I can spot from your config. is 3gb vs. 4gb ddr2 ram which is maybe worth 1k max.

With regards to the processor, I would hazard a guess and say the P8600 would be a 7.5/10 based on better performance, lower heat and better battery life. However, since you've said that you don't need a very performance driven laptop, you probably wouldn't notice the performance difference that much.

The price here is quite a bit and unless you really need the extra firepower and portability, not really worth it. Also if you need to carry around your laptop at all, stay away from the 15.4/15.6 inchers bcoz most people i know (myself included) don't like carrying around a 15.4 incher.

PS: The Dell Studio 14 is a better option than the HP in terms of performance/price and you can even add nifty little extras like the backlit keypad.