It will probably depend on implementation...certain chipsets may be faster then others.

However, anandtech recently reviewed a WD hard drive with a USB 3.0 connector and it was actualy ~20% faster then the eSATA port.

WD 3TB External HD Review

I'm sure others will note this as well, but if you multiply the width and height by 2x you receive a total of 4x resolution. (i.e. you could fit 4 1920x1080 screens into one 4k x 2k screen). Another way to say it is that by multiplying the height and width by 2 you have 4x the number of pixels.

You're assuming that there is no ongoing cost associated with this. The service will take money to be online, support the hardware / travelers, etc. However, I would guess it will still be a good money maker for the airlines.

Guess I am going to buck the trend here but I could see this being useful for kiosk / terminal applications. How many applications does that computer for looking up books run at your local library for instance.

Obviously this would not be good for you average desktop user but I see no issue for specific usage situations to save a few bucks.