A very true answer energy2, but I'm sure someone will come along to disagree.
I used Manston in the days of EuJet and at the time lived 65 miles from there. Though Gatwick and Stansted were far nearer the airport was a breeze and much like the experience you get at LCY where you step off the plane and your through arrivals in less than 5 minutes. No waiting for buses to take you to the car park either. Time wise was probably on par with Gatwick and Stansted when you take these factors into account, but I for one would much rather use smaller airports like Manston and would love to see some better passenger use made of it. Even living in London now, I'd much rather use Manston than the "big three" if we were only given the chance again, but with the way things are economically I don't think we'll see much if anything this year.