Internal geared hubs?

didn't read the thread, so may be missing somethign, but if you squeeze a 135 into a 120 you're going to have to adjust your current chainline by a whopping 7.5mm, likely, unless there's some way to adjust the placement of the cog in back... not sure. at the worst it'll be impossible. at the best it'll be adjustable at the back. Most likely you'll just have to deal with it up front and thats going to be a pain in the ass

This^

I read somewhere that an alfine set-up weighed the same as a XT set-up. This made me think that from an off-roading perspective, all this weight would be over the rear contact patch, which is great. But with only eight gears, you are basically in between single speeding simplicity, and multi gear smooth cadence. This appeals to me, it may not to others.

Also you can change gear when stationary, which is cool.
Your chain wrap is better.
Your chain line never changes.

I'm planning on putting together a extra rear wheel for my single speed 29er, with an alfine. Getting to distant trails with uber long cranks and 55 gear inches is a bit of a PITA.