A nice dilema

Surely if you're spending that much, you would test ride them. Then you will know what one is right.

I test rode my new bike twice, with a couple of months in between between before buying. Like yourself I was spending a lot of money so wanted to be sure that it was the right choice.

Personally id be drawn to the Cannondale Supersix as the bars, stem and wheels can be upgraded later for a reasonable amount although ive just noticed it has no dura ace crank which is a big let down

How about slightly used 2nd hand bikes with warranty, much more bang for your buck

http://roadcycleexchange.com/collections/allbikes/products/spcialized-ta...

They have all sorts and also sell wheels, bars, stems so if they have a bike you like but you wish to change a few things then they will accommodate this

Nice to be able to have a choice between these expensive beauties. I have never ridden any of these but have you considered what sort of riding you are likely to do. For example the Scott Addict is an all out racing machine and according to a friend of mine who has ridden one he wouldn't like to do a day ride or sportive on one because it is extremely stiff and unforgiving. Maybe you are a racer so that will be exactly what you need.

Fit is the most important... Then I'd pick the addict

I suppose you need to sit down and work out what is important to you.

Do you want Di2?
Is weight the deciding factor (what type of riding do you do)?
Do you want off the peg or customer build?
Do you want a change from a Scott Addict?

Only you can really answer these questions.

I've no experience of bikes in that price range but I like the cannondale. As you say it was good? That doesn't sound too enthusiastic. If I personally was spending that money on a new bike I'd want to be blown away. Are you upgrading from a bike in a similar price range?