Thanks for the report. Keep us updated!
I live in and near a bunch of hills. Fifth gear won't pull a lot of them so I drop to 4th and take it to 50 mph indicated. Yes, TW sings a bit in the upper RPM registers but not unbearably.
The upside to living in and near these hills are the great forest service roads. I find 1st gear is needed on some of the really big hills hidden in spots, and in truth, a couple of times I've wished for an even lower 1st!
One of the great things about the TW is parts availability and the versatility of the bike with different parts.