HI Ben (and others if you're interested).
Bought in 2018 (is the 2017 Advanced 1 model). Has been ridden <200k. I swapped the stock wheels for Hunt wheels which I'm not planning on selling, but could if you're desperately interested. Full Ultegra, discs, 105 pedals, 28mm Conti GP5000 tyres.
Selling due to buying a custom Talbot (will put the Hunts on that if they don't get sold with the Defy. Looking for £1,000 for the Defy with the original wheels and tyres fitted and £1,700 if the Hunt wheels are left on.
Here is a link to the Giant Bike Archive with all the specs - https://www.giant-bicycles.com/gb/defy-advanced-1-2017
Would prefer for someone to collect (Surbiton) but could deliver in London if required.
Happy to answer questions. Matt