I know how you feel Maggers. I've got the superlite Bianchi (summer bike), the suped up Sirrus (new wheels, convereted to drops) (winter bike) and the heavy wide tyred hybrid (commuter). I went out on Tuesday night with the club as I had to take the bike into work beforehand I did it on the Sirrus however with slipping gears it really struggled on the club run (over 19.6mph average for the 40miles) at some point on that I decided I needed n+1, with the Kinesis (racelight tk) being my favoured option and I could get it through cycle to work. I went to a lbs only to find out that they discover Kinesis aren't shipping them until August
Maybe I'll just have to tart up the Sirrus more (23mm tyres /Carbon Forks/ new shifters/ money, money)
I've also an inkling towards a fixie but I think I enjoy my hills too much.