Don't underestimate the significance of the screen size. I have both and the difference is demonstrable in use. The only advantage the 11" Air has is a greater measure portability that will only seem worth it to a small segment of users. The 13" is a far better rounded unit for general use.
The 13" is capable of a greater capacity SSD and 40% more battery charge life. Both of these can be significant factors for some users.
The sound on the 11" is nowhere newr as good as it is on the 13"
I know this now because was able to handle both for a good period of time.
Ill just post this for refference to justify this thread i know you get allot of these posts but not one i saw mentioned the sound quality comparison.
Macbook Air 11"
1366 x 768
Higher PPI (135)
5 hour Battery
Smaller, slightly lighter
Macbook Air 13"
1440 x 900
Lower PPI (128)
7 hour Battery
Better Sound Quality
Bigger, slightly heavier
I am debating going with the 11" i7 8gb 128gb ssd. And using a external monitor.
Do you guys think there will be after market upgrade battiers later?
There is a company called HyperJuice that makes external batteries -
They're not cheap but I know a few of my users (that frequently travel overseas) use one and they've very happy with them. The ability to use your machine for 12+ hours without a charge can be fantastic for in the field work or on a long flight.
I agree with SP, the screen size is not a trivial factor to consider. When I worked at the Apple Store it was a nearly daily occurence that people would bring back the 11" MacBook Air because they regretted having to deal with that little screen.
So while the 11" MacBook Air might work just fine for you, just make sure to give it a thorough demo at an Apple Store to make sure you're completely satisfied.