The N71 with the HD5730 is by far the best option (longevity-wise).
The i7s are real monsters at multitasking, even the 720M clocked at 1.6GHz (8-threaded).
However, it won't do 4 hours of battery time. You're lucky if it reaches 2.
Originally Posted by Black Panther
Even at 1.6 vs 2.26 it's faster? That was my main doubt for laptop #1...
When only 2 cores are needed, the i7 720M disables the other 2 cores auto-overclocks to 2.4GHz.
So the i7 will always be faster than the i5. Even at the same clock speed, it has twice the L3 cache.