Definitely get the RX 100 II for a travel camera. I own an x100 and use my wife's RX 100, and while I love the x100 despite some odd usability quirks (that apparently they fixed with the x100s revision), it's not versatile enough for me to take on vacation. I've missed shots where a wider angle or a bit of zoom would have helped.
The RX 100 is definitely easier to carry, and the quality, speed, and performance is more than acceptable for high quality vacation snaps. Unless you're going on vacation with the express intent to photograph (in which case you'd probably just take the SLR), the RX 100 is probably a better choice. It's also a nice complement to an SLR, while the x100 will probably compete a bit more with that 30mm prime.
Here's a couple vacation snaps taken on an RX 100 that simply wouldn't have been possible via the x100, wide angle and full zoom respectively: