IGH, Alfine, Rohloff, Sturmey Archer and frames/bikes built for them...

Precisely, seems like a bit of an echo chamber. This is the nearest I've found to real world feedback: https://singletrackworld.com/forum/topic/12-things-that-ive-learned-as-an-alfine-11-owner/

1. They don’t like torque
   
2. The Alfine tensioner is as much use as a chocolate fireguard (and doesn’t like torque)
   
3. Develop a smooth pedalling style, don’t mash
   
4. Vertical drop-outs are possible, see #1 and #3 above
   
5. Get the right coloured washers for your desired cable line
   
6. Shimano Hazelnuts are thankfully softer metal than Alfine axles (overtightening essential)
   
7. Liquid Torque is your friend, see #5 and #6
   
8. Looks like a single-speed thoroughbred, weighs like a shire horse
   9.They are reliable and low maintenance though
   
9. An oil change after a 1000km is highly recommended. Less drag, less noise, more smooth speed
   
10. KMC half link chains solve #2… for about a month until it has stretched like nicker elastic
    
11. KMC BMX chain with a single half link solves all your problems.