Although I have not attended any of the three events - the first two by choice of locations, this year because of work - I'll chime in on SD. You all know the value of free advice....

There is only one area in SD that makes sense: the Black Hills/Badlands area. Great scenery and roads in the area. Should have accomodations for tourist traffic. The state is generally motorcycle friendly.

The balance of the state offers the advantage of seeing any heavy weather and storms nearly a day before they would arrive, if you know what I mean. (I grew up on the Dakota Plains.)

Wayne