Above points are valid with regular housing.
If you use a segmented housing, you can select routing based on fit/feel preferences. Segmented housing, with a slightly wider teflon type lining and a narrow cable, allows you to make radical turns without significantly affecting friction/feel.
I use Nokons because of a prior car where I had to turn the bars a lot to get the bike to fit in said car. I blew out regular housing (campy and shimano) after a few months. The Nokons held up fine. I also run some tight turns between the bars/stem/frame, and Nokons (or any segmented housing I suppose) help with that. Finally a segmented housing allows you to "grow" housing, i.e. if you want to make it a segment longer you just add a segment (this is based on the premise that you'll be running the inner liner the whole length of the cable, which I do).
In other words I run my cables without any regards to cable friction, at least not anymore.
However... I like the feel of a "wing" bar. I run the cable in front and behind (Campy levers) the bar so that the bar takes on an oblong shape.
I just (and I mean just) bought an FSA wing compact bar and although I haven't taped it yet, I'm debating what I'll do. I like running the cable behind but I'm worried that I'll bruise my forearms on the bars when sprinting out of the saddle. I'm thinking that since the bar already has the wing shape and I want as much clearance just above the drops, I'll run the cables forward.
I usually ride the trainer without tape for a week or four to finalize lever position, experiment with housing routing, etc. Then I make the decision. I'm about 8 or 10 hours into this setup.
