Hey villain,
I am glad you are enjoying the R-D1. I have an assignment/challenge for you with your new lens on my old camera. I don't know if you have been to DC before or have yet seen the Vietnam War Memorial.
I haven't been there in many years myself, but will never forget the emotional response I had when walking down into that memorial. It was very powerful, and if you have not experienced it I highly recommend you to do so.
I think the 15 will give you an opportunity for some excellent photos of that memorial in particular. Anyway, I would love to see it again...
Also don't get drunk and misplace your car there like I did when I was 17. I actually flagged down a cop in desperation and he drove me around till we found it. Those were different times...
Enjoy your trip and if you can post photos when you return.