What Colin said. Erm, what Colin said I said. Or something.
Moultons were used quite successfully for racing in the 1960s. Particularly in team track events, where the small wheels meant the riders could draft each other very closely.... and then the UCI decided they weren't bikes.
They accelerate very quickly, too, because there's less flywheel effect with small wheels.
Any disadvantage there might be with small wheels on an unsuspended bike is removed by the suspension. Instead of the whole bike and rider moving up and down over a bump in the road, the suspended parts jiggle up and down with the rest of the bike and rider moves smoothly and horizontally. As long as those little tyres are kept pumped rock hard, it's just as quick as a 700-wheeled bike, but a lot more comfortable.
They do repay a smooth pedalling action (my months commuting on a fixie help a bit, I think). In the last resort you can honk up a hill, but the front suspension bobs big time, so you'd rather sit and pedal all the way round.
Ours are both 1980s-era AM7s, updated with modern-ish components. They cost a fair bit less than a TSR, and a whole lot less than a New Series or Double Pylon!
If you want to try one, come on over to York-ish. You'll be welcome. Or phone Shaun Moulton at Bradford on Avon and book a test ride. You'll be able to ride all the current Moultons around the test track there, and/or take one out for a day's ride.