The Kampa is very quick to take down, but not much quicker to put up than a non air awning and the footprint is also not all that big at 3.65 x 2.5m. I'm not sure how effective the annexe would be?
On the other site there was a Fortex awning up for sale at £350. They are about £2k new. I've owned two of these and if you want space [5.7 x 3m?] and quality I do not think you can buy anything better, although the Unico comes a very close second. They do take longer to get down, but if you are pitched up for a week then I don't think an extra 1/2 hr is much of an issue. They are heavy to store at about 35kg, but no heavier to feed into the awning track, in fact I found them easier.
Colin