hahah.. you do realise that you will always need more than one bike, no matter how much research you do! Infact, the more research, the easier it is to justify another bike (see threads on N+1)
Back to your question, I an hugely biased and just love the Specialized Roubaix (I have owned 3). It simply delivers. Being carbon, they are no slouches and come with real pedigree. I have ridden several century rides on them and this is where they really stand out. Comfortable and responsive. Not tried the new version with the suspension in the headset so will let others comment on this but from what I read, this bike will definitely deliver against your brief!
You definitely want to try the bikes first as they will feel different.
From experience, my last piece of advice is don't make the decision over a £100 here or there. Buy the bike you want (you probably know which one that is) otherwise it will eat away at you and will be buying another bike again soon.
Good luck in whatever you choose.