I think that looks like a very nice bike and I'm sure that you would be happy with it!
I am still riding a 15 year old Cannondale which has a good quality aluminium frame and a carbon fork. It weighs about the same as the one you are looking at. My bike is equipped with a Campagnolo groupset but Shimano 105 is very good. The BMC has a good wide range of gears.
I reckon at the price you are talking about you would be better off buying a quality aluminium frame than a lower quality carbon fibre one.
It might go against the grain to '
forget the science' but ... '
forget the science'!

You are not trying to win the Tour de France (I hope!) - you just need a nice bike to enjoy riding and keep you fit.
You would probably find it very difficult to measure any significant differences between the BMC and CF bikes in your price range. A small weight difference perhaps, but you could lose more off yourself than you could off the bike.
As Yellow Saddle has hinted at, you are probably going to end up buying a bike that you like rather than something which is much better than other similarly priced bikes. Buy something soon and enjoy riding it through the summer. If you start getting into comparing specs you could end up dithering about until the autumn. I have seen it time and time again, and the bike eventually chosen was no better than the first one looked at!