I wrote this on another forum about 10 months ago about my Sony RX100 VI. Nearly a year later, my conclusion is pretty much the same...
I spent about 4 of the last 6 weeks of the year on the road – 2 weeks in Beijing/Tokyo, and 2 weeks in Europe (Germany, Italy, Slovenia, Croatia, UK).
The first trip was a work trip (the Tokyo part anyway), and historically I would have taken my mirrorless on a trip like this – a Nikon 1 S1 with two lenses covering 30-300mm equivalent that fits (in a small shoulder bag) in my carry-on backpack/laptop bag.
The second trip was all holiday, and almost certainly I would normally have taken my DSLR, a Canon 70D with lenses covering 27mm-640mm equivalent. I have a love/hate relationship with this camera – I love the camera itself, and I especially love my 100-400mm lens for it. But it's big, and heavy, and means that I need to check a bag when I travel (as the camera + my other bags are too much to carry-on) which is something I try very hard to avoid doing.
This time, for both trips, I left the Mirrorless and DSLR at home, and just took the RX100M6.
For the first trip, I didn't miss the mirrorless at all. The Sony pretty much covered everything the mirrorless had, with the convenience of size winning out over the few benefits of the Nikon. Reach-wise I was down a little (300mm to 200mm), and as someone that often likes tight crops I did occasionally want to push the zoom a little further, but not enough to bother me. The one thing I did miss was my C-PL filter. The Nikkor lenses have a standard 40.5mm screw-on filter adapter (same for both lenses which is nice), whilst the Sony has no (standard) ability to use filters at all.
For the second trip, I can't say there weren't a few times that I was wanting for the Canon 70D, but they weren't that many... There were times I wanted my 100-400L (specifically the 400mm part). There were times I wanted my 50mm F/1.8. And there were times I wanted both my C-PL and ND filters. However on the other hand, I was happy not having to carry the damn thing around with me all day every day (as opposed to having the Sony on my belt and not even knowing it was there). And every one of my 7 flights I was happy to be carrying my bags on the flight with me. Not to mention when catching trains/etc.
Going thought the photos from both trips I'm very happy with the results. There's a few where it's clear that they would have been better with a polariser, and that's something that I'm going to have to work on finding out the best option for. Some of the low light shots might have been better with the larger sensor on the DSLR, but the combination of a 1" sensor and good high ISO performance got me close enough that I don't really care. There were some where I think the Canon would have done a better job of focusing (in particular some shots involving flames), but it's hard to really know. But otherwise the quality is at least in the ballpark of what I'd expect from the other two cameras for the vast majority of shots.
Going forward I think my Nikon 1 S1 is ready to head to either eBay or someone in my family – I just can't see where I'll use it again. My Canon 70D will still absolutely be used, but for travel I think I'm going to have to have a serious reason in advance to take it (eg, headed on Safari where the 400mm really matters), otherwise I just can't see the benefit being worth the effort.
Now of course, the Nikon 1 S1 is hardly a "current" model, and even the 70D is one (nearing two) generations behind so it's not a perfect like-for-like comparison, but still...
And to finish, one from the try-that-with-an-SLR, here's the RX100M6 on an UltraPod II strapped to a relatively flimsy tree overlooking the Edinburgh Hogmanay Torch Parade –
https://photos.app.goo.gl/25tUnsDBFzJAd8Tp9