I actually find the 5d3 In camera HDR extremely useful for travel shots.
I recently went to several places by the beach (Santa Monica etc) and with the bright sunlight, and the location of the sun, i had many shots that have the people underexposed because of shooting into the sun.
On ideal shoots, you'll use an ND Filter or photoshop to recover shadows and highlights etc…but when travelling, i don't want to have to do any of that..i don't even shoot in RAW..i want everything as simple as can be.
This is where i find the HDR feature extremely useful. For shots that have too large a range from highlights to shadows, i just use the in camera HDR and it solves almost EVERYTHING…i rather have an image where i can see everything but look "fake" than have an image that have underexposed areas especially family faces that you can't see.
here's an example of how the HDR helped…without it, the building would've been so dark you won't see it clearly at all. This is just one example..i've use the HDR ALOT during my trip since it was much easier than struggling with filters and locking exposures and taking multiple shots etc…HDR is a quick fix for normal generic shooting.