My Gazelle has a standard nexus 8, and my Robin Hood has a red band nexus 8, the only noticeable difference is the red band shifts better under load.

I replaced the derailleurs with a 7 speed Shimano on a steel Ross Mt Whitney. The hub is heavier than the freewheel hub, but I also removed 2 derailleurs, 2 chairings, 5 sprockets, a shifter, cable, and about 20 chain links, so overall the gain in weight is about equal to a bottle of water, and I'm not sensitive enough that feel that.