Intel Atom N550 vs SU2300

SU2300 is definitely out perform the N550 (3x faster, at least!!!), although it has a lower clock frequency
slightly higher TDP 10W compare to N550 8.5W , 1.5W ... will it make a big different to the battery run time ? I think it is trivial and neglectable
equip with VT-x and intel 64, SU2300 is the most competitive processor with money , performance and TDP all considered (by now)

the modern i3 series i3-330m is 35W TDP (WTF, 35W !!!) and i3-330um is 18W TDP , but there price is much much higher.

the question is, do I need a cpu with high performance which I can't use it after the battery use up? I my eye, run time is the most important factor, so I prefer the SU2300

http://botchyworld.iinaa.net/cpu.htm