I have 3 bikes:
The S-Works is a definate keeper and is my summer commuter. The Pinarello was bought for cheap, and I will resell it for a profit. The Giant is supposed to be my 'fast bike' but it's not faster than the S-Works.
I recently sold my Surly LHT. I bought it with the intention of riding LEJOG and long Audax rides, but it was too heavy and too slow. I never managed to fully customise it with racks and a dynamo hub, but I used it as a commuter and rode 2900km (and sold it for £100 more than what I paid for it):
So once I sell the Pinarello, I will be looking for a steel bike to do 300km audax rides. I will use the S-Works with a handlebar bag for audax rides up to 300km.
I'm seriously thinking about selling the Giant, and getting something like a used Scott Foil with Di2 but I'd have to save ap a bit more