An old thread this may be but I have found it very reassuring . I have just moved up from a 1200 Sportster to a Dyna and I had kind of figured this out for myself . A Harley , regardless of size does not mind being revved . Too many people seem to think that a big Harley should be going " Potato Potato " when it's on the highway but I've quickly realised that , just like the Sportster it should be going " Brrrrrrrrrrrrrrrrrrrrrrrrrrr " On English country roads the bike seems happiest in third gear but the problem is that if I do change up too early the bike has enough power to build up speed at the risk of lugging the engine . Change up too early on a Sportster and it will tell you about it ..

 

And as you know people who change gears at set speeds are not telling us whether they take hills into account and end up with folk taking it as gospel and end up labouring the engine.

The bottom line is changing gear as you say when you feel the engine is happy, it is unloaded and can take the next one.