I had a nexus 8 hub in my Surly Crosscheck on and off for 5 years, so nearly relevant, feel free to ignore etc.:
Hub gears on steel frame cyclocross notes:
The bar end shifter I had was great, and suited the wider spacing of the gears. I loved it. Still have it. Must flog it.
The hubs aren’t zero maintenance, you have to rinse and relube at 500 miles then every 2k, it’s a very easy job once you know. They are, however, dead cheap to replace chain and cogs and need a lot less maintenance. But then mine died last year with about 8,000 miles on it.
The weight isn’t a problem on road (great for commuting) and on tracks, but it’s always there. Where that extra weight in the back wheel really screws your ride is the handling on rough stuff. I found out later when I went fixed and realised the Surly’s handling is quite sweet, and climbed stuff I couldn’t manage with the gears . Are heavy gears worse than no gears? Depends where you live.
Knowing what I know now I wouldn’t choose a steel bike/hub gear combo again. That said the Alfine is better than the Nexus and I much prefer Genesis steel stuff to Surly.