Definitely go wide when on vacation. If you don't have an ultra/superwide zoom for traveling, you need to get one. I have taken over 85% of my shots on vacation with my superwide zooms. In fact, on my recent trip to Asia, I brought my Olympus kit and used the 11-22/2.8-3.5 (equivalent to a 15-30 for APS-C) for literally 97% of my pictures. Out of the 513 pics that I took with my dSLR, all but 16 came from that lens.
Just remember not to be tempted to just sit back, set it to 10 mm, and try to take in everything in one shot. The
magic of superwide angle lenses are not so much from the massive field of view (which is an important feature for sure), but rather, from the emphasis on perspective that creates visual tension, strong depth cues, and draws you into the scene, as if you had figured out how to create a quasi-3D image from a 2D piece of paper. That, my friend, is the magical property of wideangle photography.
People will think you've become a better photographer overnight and wonder what your secret is. If you want to be nice, go ahead and tell them: "the secret, my friend, is not very big at all... in fact, it's between 10-20 mm in length"... and just walk away while they scratch their heads with a puzzled look on their faces