Just got back from 1400 miles on my 2008 Springer out West. Shipped the bike into Rapid City, SD, and out of Jackson Hole, WY. Did the "greatest hits" over a 9 day period in South Dakota, Wyoming, Montana and Idaho. Springer ran like a champ. Saw the Black Hills, Rushmore, Devil's Tower, Bighorn Mountains, Chief Joseph Highway, Beartooth Pass, Yellowstone and the Grand Teton range. I'd done all this on various car vacations and promised I'd go back on my bike.
Used a sissy bar with a T-bag. Worked great. No problems of any kind. Climate ranged from under 60 on top of Beartooth Pass to near 100 in high desert on way into Cody, WY.
My Springer's got a set of Bub 7 2 into 2's, a 14" Windvest Windshield and a fixed Sissy Bar. I also installed a Kuryakyn Stirrup Heel Rest on the right side footpeg.
Was comfortable throughout. Longest single-day ride was 280 miles from Custer State Park to Devil's Tower to Buffalo, WY.
Never really uncomfortable. I expanded the T-Bag late in the ride and was glad for the support on my back, but could've lived without it.
Took the Skilled Rider Course before I went (I just got the bike last September).
Did the route on Harley Ride Planner and can email if anyone is interested.
No dings on the bike, but I killed a million bugs.
Rode it with my buddy who's got a Heritage Softail Classic.
I'll post a picture or two.