I have a SRAM Dual Drive on my commuting bike and the usual derailleur system on my brevet/century/weekend fun road bike.

I never want another commuter bike without an IGH. In addition to shifting when stopped and protection from the elements, my setup is also very difficult to damage from falling, colliding, being stacked, kicked, etc. (no exposed parts) and allows access to all 24 ratios, since cross-chaining is not an issue.

Given unlimited funds, it would be a tossup for the road bike. I might prefer an IGH there too, because the time I save on not dealing with derailleur issues could compensate for any miniscule energy loss. If I were a serious racer, I'd skip it, but I'm not.