I rode them both and loved them both! I am totally torn. I am not sure that I can make a wrong choice, as they are both great.
Kurt, I bought an RT in March 2008. I didn't know if to get a 1300GT or the RT, so I basically tossed a coin. In March '09, after only 4500 miles with the BMW, I bought the C14, and had them both in the garage for one year, in which I did 500 miles on the RT and 10 thousand on the C14. So, in april 2010 I sold the BMW. Not one bit of regret. As you say, it is a comfy bike, well made, but didn't light my soul. My Suzuki Bandit 600S was a bike, while the BMW was a car on two wheels. It got the job done, but every time I walked away from it I forgot it existed. My C14 makes me feel nice about life, the BMW didn't. The BMW was a tool, a Ducati would be a lover, and the C14 seats in the middle, with the sum of both aspects being higher than in any other bike I ever drove (and because of my job, I drive many).
So, as you can see, this is a very personal issue. I could point out that I lost some few thousands on the "BMW experiment" by buying and selling it, but this is bikes, not shares, and I do it for pleasure, not profit, so I won't even mention the details. It may be important to mention that I don't see vibrations as character, but as a nuisance, so in my book the more cylinders the better.
I also discovered that to me the cruise control is not that interesting on a bike as it is on a car, so I went with the GoCruise ($17) on the Kawasaki and it more than covers my needs. I also fitted her with grip and seat heating. Basically, I have almost* the same creature comforts as in the BMW, for a lower cost, more power, same reliability in my case, at least thus far; I sold the BMW with 5000 miles and the Kawa has 25000 miles, both had zero issues to report.
*The only thing missing is the ESA suspension. I'd gladly pay those $700 extra to get it. Or more. Are you listening, Kawasaki?!!!