There are a lot of hills in Cornwall. I am always going up or down, like being stuck in a game of snakes and ladders, so the overall weight could be an issue. Useful data on the relative speeds though. It confirms what I suspected. I really like the look and feel of the CdF though. Maybe I need more than two bikes....! I read your thread on the CdF and it was incredibly useful. There is an argument for consumer reviews of bikes on this site, rather than reading 'professional' reviewers.
That's a fair point about the hills; although again to put the mass into perspective on a relatively optimisting value of 80kg all-up (rider, bike etc) a difference in bike mass of 2kg is only 2.5%, so on a fairly steep hill where aero isn't a factor you'll be 2.5% slower or have to put in 2.5% more power to maintain the same speed.
Don't get me wrong, all things being equal I'd always rather have a lighter bike.. I find lightness makes a bike feel tangibly more agile / "lively" / responsive especially when out of the saddle and over rough ground when you need to throw it about underneath you. Of course this needs to be balanced against other factors such as robustness and longevity since improvments in one area will always mean a price is being paid elsewhere.
Personally I love my CdF but it doesn't feel as agile as the road bike. Granted some of this will be down to the more "stable" geometry as well as the weight. IIRC the CFRP fork (as used on the Ti variant) loses maybe 1kg, however being tight and prone to anxiety I was more than happy to take the mass penalty on the fork for the peace of mind it brings in terms of robustness / predictible failure characteristics.
I don't want to come across as one of those owners who attempts to railroad others into making the same choices as they did. I've only ridden the steel CdF so my observations can only really be confined to geometry and general build relative to your situation, so is only partially relevant - while I've no experience of the other two models you mention so can't give a valid comparison.
I'm glad you found my CdF review of interest anyway; while I make no claims about my skills as a reviewer I'm a firm believer in the value of unbiased owner reviews to help those in the market for a new bike make a fair and informed decision on where to go