Good article.
HTML version here.
http://www.findarticles.com/p/articles/mi_qa3748/is_200404/ai_n9389476You can run your own numbers here.
http://fermi.la.asu.edu/w9cf/tran/index.htmlAnd you can also factor in losses in the tuner (something the article didn't do) here.
http://fermi.la.asu.edu/w9cf/tuner/tuner.htmlGood info on the loss in the major types of commercially available ladders lines here (and some info on tuner loss too). From Wes Stewart, N7WS.
http://users.triconet.org/wesandlinda/ladder.htmOn the above page there is a link to an article on ladder lines by Wes. In the article he measures the loss of wet ladder line. It is MUCH higher. In the article and on the page he does point out that these numbers probably represent the worst possible scenario in actual use/practice. That said, they are something to consider, especially if you are going to have long runs and live in a wet location or one that get a lot of icing in the winter.
http://users.triconet.org/wesandlinda/ladder_line.pdf