I am toying with the 8 speed, I am not mechanical at all and struggle with maintaining the rear dereailer without the cost of shop work. I was thinking about just popping on some Marathon Plus’s, SKS & racks and bobs ya uncle we have a tank of a commuter.
Only downsides I can tell is the weight, the lack of gears and the cost of servicing it.
weight: yes but barely noticable when riding along, and think of it as extra training,
lack of gears: No. simply a more efficient spread from top to bottom with no multiple overlap combinations doing exactly the same job inbetween. I can manage 90%+ of my regular uppy/downy routes on a 3 speed Brompton and 100% on an Alfine 8 700c Ute bike as I can on my old 3x8 CX or current 2x9 roadie.
cost of servicing: Couldn't tell you, I've only had the Alfine for 5 years so far, ridden thousands of miles in all weathers and road conditions.
New chain and a minor adjustment to the EBB by me is all its needed to keep it silent and smooth, I even had it assessed by a pro mechanic pal 18 months ago as a precaution, he refused to take my money as there was nothing he felt he could do to improve it.