Why a 17"?

Those of you that have or are contemplating a 17" MacBook Pro what's your reason?

Is it screen size? The extra power, ports or?

My reason would be strictly for the added screen size, compared to using my MacBook Air all day as I do now, the larger screen would be more pleasurable and productive to use. I don't really need the extra power.

Ideally an ACD would be best, then you're getting the ultimate in screen size, but I move around too much to want to be tethered to an external monitor.

Now I use my 11" Air the most, so easy and fun to use anywhere or anytime, but using the small screen all day is probably isnt the wisest move for productivity at the least. I have a desktop computer, never use it because I'd rather not work from a desk often.

Using the 11" is something I know I should get away from but can't seem to break the habit Reason is not wanting to have the weight of the 17" on my lap all the time and carrying it around is obviously a huge difference.

Anyone go from an Air or smaller screen computer to the 17"? How do you like it?

I think the trend is going the other way ... People going from 15/17" notebooks to smaller machines, like the Air for example. What to do?