Well I'm back from holiday and need to update:
Wrist strap:
I ended up buying CORDY CLASSIC LITE from
https://www.cordweaver.co.uk - it was something I spotted on here. A helpful chat with Brian from cordweaver led to me buying the Cordy Classic Lite. It fits my wrist well and I love how it closes down to become secure. However, this same feature made a bit difficult to take on/off repeatedly when handing the camera to others. Still better than the WS20 that I had for the G5X.
Camera:
In some ways, very familiar to the look and feel of the G12. I'm right handed so easy to hold in one hand, with wrist strap keeping things secure. Changing aperture and/or shutter speed was easy but changing ISO meant I had to continuously use the touch screen rather than press a physical button or dial. For the most part, I was happy to run around in aperture priority and auto-ISO, and use EV compensation to adjust if required. The camera did seem to have a tendency to overexpose a shot, even outdoors in bright sunshine. I have no idea why.
Touchscreen - I very rarely used the touchscreen but it was quite sensitive, easily moving the focus point when I brought the camera up to my face to use the EVF. My nose would touch the touchscreen and move the focus point. This frequently led to incorrectly focussed images particularly if I gave the camera to someone else to photograph a group with me in it. I also needed to use the touchscreen to change the ISO if I wanted to override the camera's settings. I miss the ISO dial from the G12.
EVF - a revelation. The optical tunnel in the G12 was useless since it gave no idea of what you were focussing at nor what you had composed. It was easy to use to compose images and get an accurate representation of what it would look like. My only minor niggle was the sensor to turn on/off the EVF (and hence turn off/on the rear display) was again sensitive. I would frequently find the rear display to switch off if I brought the camera too close to my body or if my thumb would pass over it when previewing images.
Images - I'm still going through the images in Lightroom (after having to switch from LR5 to LR6 as only the latter supported the G5X). I was frustrated with the inability to apply a lens profile until I realised the camera applied its built-in profile. Wide open, the images are soft. Stopping down the lens improves this. High ISO produces a lot more noise than I was perhaps expecting. One of my first shots on holiday was the wife and I travelling in a car and we took a selfie using the camera. It decided to go for 12800 despite being wide open at f/1.8 and hence produced a very soft but grainy image which isn't easily correctable in lightroom. General images are otherwise great with good shadow detail and some reasonably good image quality when cropped down in LR6.
Battery life - Reports suggested a shorter-than-expected battery life for a camera of this size. Certainly it had a lower CIPA rating than the battery for the G12 but that was twice the size of the battery for the G5X. I bought a second battery but generally found only a few days where it came in useful (mainly when using lots of flash).
Tripod:
I ended up buying the Manfrotto Pixi Evo as a travel tripod for occasional shots. Generally it was easy to set up and use but the G5X's touch screen frequently got in the way and I'd have to close it, attach the tripod and then open it again. Despite extendable legs, there were times when I still felt it was a tiny bit shorter than I wanted but worked okay as a stand-in for a real tripod. I often would use it to perch the camera on something else to give height.