Of course our users could be seeing something completely different.
How true, IMO they are seeing something very different and the same applies to each user.
Is there any way nowadays to judge what the "average" user sees in the G SERPS?
For me, I have totally given up trying. If I look at Analytics real time and see a search term that was used by a user I sometimes try and see how that term ranks
I use a totally different connection (and it's a different IP) on a totally clean browser and time and time again the user has to be going down to the fifth page or so to find my site. It's not possible - we are all seeing wildly different results.
I think country, language setting and whether mobile or desktop are the main variables to consider, though I've barely looked at mobile. Those are going to lead to different flavours of 'the default'.
It then depends on whether the query is location specific or commercial as you're more likely to see local businesses based on your IP/location setting. It's possible to be top #10 in London, UK for example, but barely in the top #100 in another city in the UK. The URL in the SERP can also be different.
Then it's down to the ultra-granular user specific stuff based on cookie/account history. That's the general gist I get from checking ranks on G from many different locations, but by no means have I done a detailed analysis.
I can't swear that it's that accurate, but what I do is using the "clean" browser, change your location settings on the G search page to the location of users who used those terms and you should see something you'd expect. I usually do.
For a generic view switch your location to just "USA" for US search results. I haven't tried using other countries like "UK" or "England".