Fixie vs Road Bike - the right fixie bike for bunch rides
Disclaimer: I am a fixie hater. I'll try to answer this as if I was impartial.

Proper road bikes (Including the Moulton) are the machines for speed, and always have been (unless you're on a velodrome).

Looking at it through a speed lens, a fixie has a slight weight, aero, and drivetrain efficiency advantage over a road bike, but this usually doesn't come anywhere close to offsetting the disadvantages...

It does not have the top end speed and can't accelerate like a road bike because of the gearing. It is horribly inefficient at climbing. If you're hardcore and you ride with no brakes, you have to ride more conservatively because of your poor stopping ability.

On long rides, you will find yourself tiring sooner because you won't be able to ride at your optimal cadence.

The guy on the orange fixie has good legs. He would have been just as fast (if not faster) on a road bike.

Whatever you do, don't "sell all your bikes for THE ONE fixie".