Purchased the Hitachi Travelstar 5K160 (HTS541680J9AT00) as a replacement drive for an ageing Sony Vaio K100 laptop.
If you're in the market for a fast 5400 rpm laptop drive, then the Hitachi 5K160 - 2.5" Hard Drive should be given a very long look. Acoustically this drive is far superior to the pre-installed 4200 rpm 2.5&" drive which before was the loudest item in the system.
Since installing the drive there has also been no noticeable increase in temperature or fan speed but there has been a slight improvement in battery length.
I recommend the hard drive especially for those laptop owner who still use a 4200 rpm HD. It's worth for every penny!