Good shirt, but...
Don't get me wrong, the R.5 top is a good shirt, lightweight, warm, and comfortable. But so is the midweight capilene shirt. I bought both at one time or another and use them primarily on extended rafting and camping trips (so believe me, I put them to the test), and to me the midweight capilene and the R.5 are pretty much the same--except that the capilene's cheaper. Whenever I pack, the first thing on my list is that midweight capilene top. The R.5 is just an extra.