The Rockchip in the R6S is very powerful, though depending on what you want to do there may be better options. The R6S doesn't have hardware offloading in OpenWrt. Many Mediatek Filogic SoCs do, so they can do NAT, routing, PPPoE, etc. while the CPU is almost idle. Banana Pi R3/R4 are good options or if you want something that is more of a ready-to-use product and doesn't requite SFP modules, the GL.iNet MT-6000 is really cool: https://www.gl-inet.com/products/gl-mt6000/
Runs their fork of OpenWrt with a user-friendly interface (though LuCi is also available) and you can also flash vanilla OpenWrt. They also have smaller travel models.
Of course if you use stuff that needs to run on the CPU (like Cake), then the R6S will be faster.
I personally own a Banana Pi R3 as my main router and it's awesome. Unfortunately, it is pricey and pretty big for a travel router (besides the fact that it must be assembled). The MT6000 is even bigger. And you have to carry an extra power supply.
For traveling I use a Gl.inet Beryl (GL-MT1300), which is nice, but not very powerful. Nowadays I would probably go for a GL-MT3000[1], if there wasn't the NanoPi R5C, which is small, powerful, supports OpenWRT and has Wifi.
As a note: I thought about having Wifi via USB, but the stability and performance of USB-Wifi is nowhere near the integrated / miniPCIe stuff. So if wifi is a requirement, this might be important.
If this is too expensive, you could also go for a NanoPi R4S[3], but I wouldn't. The N6S is worth the additional cost.
If you need wifi, there is the R5C[4].
1: https://www.friendlyelec.com/index.php?route=product/product...
2: https://openwrt.org/toh/views/toh_available_16128
3: https://www.friendlyelec.com/index.php?route=product/product...
4: https://www.friendlyelec.com/index.php?route=product/product...