Erm no. My 12" Powerbook lasted for about 5-6 hours. 4 hours is a definite step backwards from that. My current laptop is a Thinkpad x200, which goes for at le

Erm no. My 12" Powerbook lasted for about 5-6 hours. 4 hours is a definite step backwards from that. My current laptop is a Thinkpad x200, which goes for at least 8 hours of real use (the manufacturer rates it at about 11 hours).