I have an Alfine 8 on my winter bike.

To me there's 2 good uses for an IGH - winter road riding, and bike that are left outdoors 24/7 (like city bikes are). I have not had the numerous issues that above posters had. Mine had slipping issues but then like someone said I got the cable adjusted (same thing you have to do with a derailler) and it's worked great since then. After like 5 years the shifter got gummed up, and I had to pay a local shop $30 or something to clean it out. Was kind of odd. But the hub itself has continued to work well.

I wouldn't really recommend it for summer riding though. The maintenance benefits are a bit overblown for summer riding imo, it's only worth it in the winter because of how much salt and sand is thrown up, and not icing up the cassette so you can't shift, neither of which doesn't happen in the summer. It's heavier. It's a little slower. I wouldn't say it's horribly slower, but I'd say I can just barely tell the difference. Bigger annoyance is having bigger gaps between the gears (at least on the 8). And a few gears are more noticeablyless efficient, though I don't use those gears very often so it doesn't matter that much. It's a real pain to change a flat on to...perhaps with practice it would be the same amount of effort, but I'm to lazy to do that.

I don't think IGH's are supposed to be put on mountain bikes that are actually ridden offroad. There's quite some debate on it.

I would stick with a regular traditional derailler for spring/summer/fall, imo. Both SRAM and Shimano have a more reasonably priced 1x11 derailler setup nowadays to which looked interesting. If I was going to do something niche and interesting on a summer bike, I'd skip the IGH and go with the NuVinci CVT bike hub with infite gear ratios. I mean it's even heavier, but it's rather interesting. Though I can't see myself doing niche stuff like that nowadays, I'd go with 1x11 myself.