If ya buy a Bently and it breaks down, then you might get mad at Bently and question their quality or commitment to customer satisfaction.
I have owned 3 new Harleys in the last 10 years. I have logged about 104,000 miles on all of the 3 bikes put together. They only bike that I had any issue with, and it was not a quality issue was my 07 Road Glide. I didn't like the way the bike ran when I bought it, but for $1200, I put a 103ci kit on it and was very happy with it.
Harley has a quality product, and the 40-60 year old riding group prove it out. As of 2009Harley still has the biggest market share of sales for the Street/Touring motorcycles in the US at 28%. Honda has about 24% and the other 2 you mentioned BMW and Triumph have about 1% each.
You need to judge the quality of a product for yourself, look at things that matter to you, paint, fit, finnish, is the dealer treating you good, do you like the bike, does it do what you want it to.
If you really feel the need to compare a Harley Touring bike to another manufacturer consider this:
Harley Ultra $22k- Honda Gold Wing $23k, The Ultra'll lose $2-3k right after you sign the paper, the Gold Wing'll lose $6-8k.
Harley has 857+ dealers across the US and countless Factory Authorized repair shops. Honda has more Automobile Dealers than they have Motorcycle Dealers in the US and there are very few Honda Motorcycle Repair shops. The argument of saying "they don't break down." don't hold water because they are mechanical with electrical and computerized support systems, they do break down and when they do, for a Honda, it usually means a trip home on a hook.........That'll ruin your vacation.
Finally, Harley has a book full of MoCo parts to customize your bike to fit you, your style, your needs. The biggest parts dealer in the world for the Honda Gold Wing is JC Whitney, they have about 10 pages of trinkits.
As for me, I've owned Hondas, Kawasaki's a Yamaha and Harleys.......I have always been happy and preferd Harley and I would definetly buy another one.