The Harleys were the most comfortable, but only for the first 8 hours. I rode for 12 hour shifts. After 8 hours on the Harley, riding aggressively, you feel every bump in the road. Since you sit like a chair position, all the impacts go straight into your spine.
The BMW was a lot more agile and a hair faster... still slow as fukc. Although it was pretty easy to get the front tire up when I wanted. Because your feet are under you in a "riding" position it's a lot easier to absorb impacts with your legs. That let me ride longer. Still, even the 1150 was sloooooooooooow... The other tough part was that our BMWs were maintenance hogs, always in the shop. At $125 per hour of labor, it was killing our budget. It cost $1200 to $2,000 for a clutch replacement, and I needed one of those almost every year.
The ST1300 is borderline suicidal fast. We had the option for the Kawasaki Concourse 1400, but agreed one of us would probably die. This Honda will not die either. I've been run over, I burnt the clutch in competition, and it'll still hit 135 on an empty Sunday morning freeway like it's a cruising speed. The Concourse is also a lot fatter in the rear, making lane splitting pretty hazardous. The Honda isn't as impressive looking as the Concourse or even the new BMW 1200, but performance and maintenance win out. A complete Honda clutch job is only $400. The only negative I find on the Honda is that because it's so easy to ride, I forget to stop and drink water. Often going 6-8 hours with nothing to drink. I got dehydrated so often that I had to schedule Starbucks meetings with my partner so that I'm forced to stop riding.