When I do long SOTA hikes at high elevation, I usually take along a very light weight radio, that is, on the order of 6 -7 ozs. Usually that means my Steve Weber, KD1JV, designed ATS-4 or an MTR. The radios are CW only and have limited band selections. These radios light and efficient. However, there are times when I don't mind carrying a slightly heavier load if I want more flexibility with bands/modes. While I have a KX-3, I find the FT-817 to be my radio of choice. It's easier to pack, takes less space than the KX-3, even with a T1 Tuner, and just feels a little more rugged.
There is a company called AMP-3 that has developed a very nice pack/bag to efficiently transport the FT-817, power supply, cables, connectors, log, etc.. I used this bag in a recent activation in New Mexico and was impressed with it's practicality. I have no financial interest in AMP-3, other than I've sent them a lot of money for their products.
Below is a link to a video of how the pack works.http://www.youtube.com/watch?v=c_pUIzlqzKU
Also he web site address is:http://stores.amp-3.net/-strse-73/Custom-Made-Yaesu-817/Detail.bok