I hook up to a 24" screen at home and two 19" screens at work. I connect the second one with a DisplayLink USB video adapter made by Diamond. I am happy with the 11" screen when I am out and about.
Do you also use another keyboard and mouse? That seems like it'd be horrible to have to navigate that big of a screen with such a small mouse/keyboard.
hehe. Have you still not made your mind up about getting a 17" to work away from your desk?
I am actually considering going back to a 15" or a 17" when the 2012 refresh happens. I am finding that I cannot get on with the MBA's screen angles. I've owned it since 2 days after it was available and I still love it for travelling and it's ok if I am sitting at a desk, but if it's on my lap the contrast is funny to me no matter what brightness I select. I still love my MBA, but I was recently using my old 2009 MBP and I was reminded how much better the screen is, despite being glossy.
It's just better suited for my purposes - I mainly stare at text all day to make money. I've been to the Apple store and played around with all 15" and 17" models. The choice is now down to the 17" AG or the 15" AG Hi-res.
The AG screens on the MBPs are beautiful and perfect for my uses and the 1920 x 1200 resolution of the 17" is just wonderful.
The only thing that concerns me is the size of this beast. You don't realise how big it is until you actually see it in person.