Summary:
A good product - slight disadvantages of size and weight etc. compared to the 6 cell, but in my opinion far outweighed by the extra time the laptop can be used without being plugged in. Quite expensive but well worth it
Detailed Comments:
I bought this notebook battery because I wanted more battery life from my laptop - I was very impressed. Previously I had a 6 cell battery, which lasted about 2 hours in normal use (I think it's supposed to last 4 hours, but in my experience it never did). This battery does exactly what it's supposed to do - it doubles the battery life of your laptop.
The only thing I was a bit surprised about was the size - I imagined that it would be the same size as the 6 cell battery, but in reality it is about twice the size (fits in the same socket but sticks out of the bottom of the machine. Initially I thought that this was going to be a pain, but it turns out to be better. Ok so it doesn't fit in my laptop bag quite as easily, but it still fits (and even fits inside my neoprene skin as well). However, the battery means that the laptop is kept at an angle which makes it easier to type on, and most importantly improves the ventilation to the bottom of the laptop to keep it cooler (there is a bigger air gap underneath).