I've been riding with an Alfine 11 on my Swift for a few months now. It is very quiet; all I hear when pedaling is an annoying squeak from ??? (still to be fixed). The 400% gear range is plenty for me, and if they could cram the same range into just 8 gears I think I'd be fine with that. I am often taking two gears at a time when I shift.
A significant advantage for IGHs and this hub in particular, on a small-wheeled bike, is that the torque input to the hub is reduced vs. a full-size bike. There were a lot of reports of broken Alfine 11's due (it seems) to some combination of poor cable adjustment, and running with a front/back tooth ratio smaller than the Shimano-recommended 1.9. That's pretty easy to do on a full-size, especially a mountain bike! On my Swift the ratio is 50/18 = 2.8, and I have contemplated 40/18 = 2.2 for heavy loaded touring.
The flip side to babying the hub thanks to our small wheels, is that the RPMs, and hence drag, is higher. I have personally not noticed much drag from the Alfine on my Swift, but the Swift has drop bars vs butterfly bars on my old commuter, so I have no real apples-to-apples comparison to make.
Re: servicing, there are nice step-by-step directions for taking apart the Alfines, but I wouldn't dream of trying it myself with any hub. I'd probably lose a magic spring or strip some threads.