I use to travel with my cat, Spore (the one in my picture). Problem with cats is they like to go prowling, and even if they don't wander far, this can be extremely bad should you need to get the hell out of your area in a hurry and you can't find your cat. I eventually left my cat with my mother after one memorable day when I was out in the woods, frantically trying to find him while a tornado was touching down... We did find him, and all got out safely.... But we were LUCKY.
I now travel with two dogs. My Blue Heeler, and my husband's Pitbull mix. It can be difficult at times, but they add protection and companionship that no person can give. We don't train hop, and I'm not sure I'd put them through that kind of stress or danger, but they do love life on the road and being with us 24/7. AND you always know where they are. I'll stick to traveling with dogs from now on.