No need to worry about battery life in the dual sleeve, in my trip up north with the backlight set to go off after a couple minutes i was able to go for over 3 hours w/o issue and that's with MS being saved to the 5 GB PCMCIA card. Which brings me the reason why you would want a dual sleeve, storage (since the 3630 does not have an SD slot). Regular CF, microdrives and the full size PCMCIA's are coming down in price so if you actually do more than stumble (movies or music) you might want the added storage. Otherwise I would think the expansion pack plus would be fine. Yes, the brick makes your rig large but i think it's worth it, the dual batteries really do extend the life. I also became very happy when I finally found a decent sleeve to
use
Just thought of something else, if you decide to do a dual boot you would want the dual sleeve and get some type of memory card to store linux on.