Thanks for the comments Woody, Guy, Peter and Arne.
Arne, I was concerned about focus too, but it is much easier with the module system than I would have imagined. The large head is very bright making manual focus in the viewfinder relatively simple. My set-up for the crane shots was literally hanging the lens out of the car window. I didn't have time to set up a tripod or I would have missed getting the chick. All the credit should go to Leica for designing such a marvelous system. I received the 2X module yesterday, so those were some of my first images with it.
Here's another example. I drove around for an hour this morning to see if I could find the cranes again, but could not find them. Instead, I came across this group of wild turkeys. As soon as they saw me, they started to run away. This time, since I again did not have time to set up a tripod, I stepped out of the car with the lens and fired off a series of shots handheld (with arms twitching) into the bright morning sun. They all didn't turn out, of course, but I did come back with a few very nice ones. This was at 800mm, f11, ISO400 and 1/250 of a second.