I don't know of any units which plan routes based upon gradients, but some units offer 3d first person views and when using normal 2d map layout the elevations are shaded (if you have elevation data in your maps). So you plan a route yourself while scrolling around.
Yeah they are amazing for cycling. I've found bike stores in the middle of nowhere (some guys garage) when I really needed them (once in Quebec with a broken chain, and once in New Brunswick with a slashed tire which was patched but wouldn't hold for a full day).
It's also a lot less likely to miss turns, but when it happens, you can find out if continuing on will be okay or if you have to turn back.
It also takes a lot less time than handling paper based turn by turn directions, and it allows you to improvise so if a road surface is great you can stay on it and not worry since with a GPS device you will know if you're going parallel to the original route or not. e.g. On this recent trip I shaved off a lot of distance near the beginning v.s. this previous route (speed data in the last link is junk/a bug).
Regardless, google/youtube flagged the audio and the dispute has been open for a month. In the dispute filing, I pasted the relevant text from the license and linked to it.
The video itself clearly has a link to the artists site at magnatune (as required). So if any person were to intelligently go to the site and read the license or just read the dispute data I filed, the problem would cleary seen to be valid and legal.
But I'm still waiting to hear back from WMG. The point I have is that Bono's technical suggestion to track everything will not work. In a very closed and controlled environment like youtube, the false positives are so numerous that legal content cannot be cleared and shared.
Here's the license from magnatune (from link above).
"If you'd like to use Magnatune music in a video that will be posted on YouTube,
... simply buy the album and use the music. ... you're required to include attribution of our music.
If they can make penicillin out of moldy bread, they can sure make something out of you. -- Muhammad Ali