No advice on choosing a bike from me as I don't think you've yet said what you are looking for other than 'road bike'. Speed, distance, time trial, touring, all-roads, commuting... there's a lot of things a road bike will do but some of them cover the bases better than others.
One thing I would say is...
...but made it very clear after 2 test rides that they would like to see the back of my shoulders...
... go and get your deposit back. There's no way you appear ready to sink over a grand into a bike and they are just squeezing your wallet until the money drops out. Any shop that shows any sign of displeasure at you test riding bikes is not worthy of £5 on a new inner tube, let alone £1,500 on a new bike.
Pressuring yourself like this won't help anyone other than the person who buys your bike from you in 2 years at 1/3 what you paid for it with only 30 miles under the tyres. Although, that said, send us your phone number as we're about the same height and I'll have whatever you buy off you in 2014.
FWIW, I've got 3 road bikes, total cost about the same as the Secteur Comp with hugely different designs, uses and personalities. There are very few times that I have to choose between two, the nature of my planned ride and the bikes means that only one is suitable.
