I've replaced my Ribble's Campag Athena groupset with SRAM Red (bought second hand but in great condition with a Force Cassette for a price that I couldn't resist). This, along with changing the wheels to Zondas has reduced the weight of the Sportive Bianco to 7.52 Kgs. I think the weight difference between SRAM Red and Athena is about 185g. Much as I'm a fan of Campagnolo, the SRAM Red goups is excellent.
The ProVibe seatpost has also helped a little, as has replacing the supplied saddle with a Fizzik Aliante, although the latter change was more to do with comfort than weight saving. Again, the original seatpost was only replaced because the original was a bit bit rubbish and there was an irresistable discount on offer.
A big brand bike with decent wheels and weighing around 7.5Kgs (for a Large) is normally going to cost around £2200-£3000 + so I think I'm doing quite well with the Ribble. It may not be the choice of the bike snob but there's little wrong with it that I can see.
Now if only I could get it to shift into the big ring a bit better....
[Update: Will swap Red front derailleur for a Dura Ace one after advice received. Shifting between the front chainrings is vital to me (I had a nasty crash once when the chain fell off when I was out of the saddle). Using this drive train calculator I can see it's compatible]
Will post once the Dura Ace mech is fitted and tried out.
[Latest: The Dura Ace front mech helped a bit but I decided to change the bike to one with an electronic groupset to help with the front shifting - see later posts.
Top tip: I made much more by selling the frame and groupset separately, than I would have selling the bike as a complete unit.]