I'd definitely take the 20% travel job over anything else. I spent 8 years bumping around the world, with the occasion to actually sight-see anything maybe 3 or 4 times. Often that was due to a lucky local holiday where I had to extend beyond for whatever reason (meeting on Tues, Weds local holiday, Thurs more meetings).
Like was posted on the first page, the man never saw the Eiffel Tower except from an airport taxi. That's how I felt.
One observation about saving money via per diems, it really depends on where you are. My company paid $45 per day for all incidentals and food. There was not much to do after a long day, except hang out at the hotel bar...at $10 for a drink. That plus meals definitely put me in the red most trips.
If I was trying to take money home by eating on the cheap, I'd pick up dinner at Burger King. And then I gained 20 pounds in doing so.