6 cell vs. 9 cell battery on the Studio 1555

I'm looking to get the Studio 1555 and the only thing I'm not sure on right now is which battery to get. Is it true that the 9 cell sticks out the bottom a little bit? I would just go for the 9 cell, but I use my current laptop on my lap a lot and I'm worried that if the battery sticks out the bottom it would be uncomfortable since the laptop would be resting on two points rather than the entire bottom. Anyone use the 1555 with a 9 cell on their lap and can comment on that?

On a side note, what kind of battery life are people getting with the 6 cell and the 9 cell?

 

I have a 1535 with the 9-cell battery that sticks out. It's really not uncomfortable on my lap. And on a desk, it's fantastic because it puts the whole keyboard at a comfortable angle.

If I were you, I'd get the 9 cell and then get a cheap 6 cell from eBay just in case you need to be perfectly flat. I have both, except I went the opposite direction; I bought the system with the official 6-cell battery and then bought a cheap 9-cell on eBay.

On the 6-cell, I get around 3 hours of battery life on Power Saver mode, and around 5 hours with the 9-cell, using the same settings.

 

http://www.youtube.com/watch?v=2igtBNph6Gc

http://www.youtube.com/watch?v=PUQOV24lwnc&feature=related

Take a look at these videos. In the first, you can get a good look at how far the 9-cell sticks out (around the size of a AA battery). The second has a number of different tests, one of which is battery life; for each test, you can expect that a 9-cell would give somewhere around 50% more life than the 6.