I love my 5D3 and fast lenses, but I hate to carry them very far. If I'm on vacation I want to relax and not feel like a beast of burden. Since I wanted to stay in the Canon line, I use two smaller Canons when I travel. For motorcycle trips where space is really tight, I carry an S100. For car trips, I use a T2i with the rather nice stabilized kit lens.
Although the images don't have the smooth, fine detail of full frame images, they are perfectly usable for posting on the internet, which is where most of my photos end up.
I look at these small format images as a challenge to my processing skills. For example, I recently started using Photomatix to do 3-exposure HDR images with my T2i. Although the two images below were taken with a light tripod, I've had really good luck doing this hand held using the exposure bracketing function of the T2i.
This is Diablo dam near Seattle:
This is Dry Falls, also in Washington state. The tiny objects along the horizon are large grain silos. Who says you can't shoot landscapes with an APS-C sensor? LOL
A center crop:
Debating the best photo equipment for travel is fun, as there is no best answer. It all depends on what kind of photos you take, what you do with them, and how sensitive you are to weight and bulk in your pack.
One other thing I take into consideration is the cost and what happens if my equipment is lost or damaged. I get a little paranoid carrying my expensive gear on trips, but if something happens to my obsolete T2i, I won't feel bad at all.
Edit: my images got cropped to a square format by the forum software, sorry about that.