Well after lots of umming and ahhhing I decided to bite the bulit and go for an alfine hub. The whole package (shifter, sprocket, nuts etc) adds just a smidge under 2lbs to the overall weight of the bike. I fitted it to my 29er scandal slot dropout jobbie, it was very easy to fit no filing needed anywhere. Got out for a quick spin last night and I have to say I was very impressed, didn't really notice the extra weight over the back end (did a few jumps, drops etc). I deliberatly shifted under load, while not pedaling, when stationary and apart from a bit of cable stretch it worked flawlessly. I would say that there was hardly any noticable drag but in gear no4 it felt abit "spongy". Overall I would deff reccomend it to anybody that's thinking about it. Will keep you posted on long term use. 🙂