In the US its usually just US, for EU its no guarantee you will be in shengen area all the time, if it was I dont think it would be any different from US, so visa every visit.
I think PyCon US seems more central for an LS imo for the reasons I thought it was for, recently the goal shifted so its not one I really feel if I missed it would be dreadful in terms of consensus for things.
Of course there’s the valid point of many core devs in Europe to justify the rotation.
I think 70% folks can make it whether in US/Europe which like all things its impossible to optimize for every case.
Also I think if you came to PyCon US you can hit many birds with one stone in one place historically, which is a personal observation obviously.
We discussed this at the core sprint in Cambridge and people were generally in favour of alternating, although we thought it a good idea to open a poll to gather wider consensus from the core team.
And we felt the poll should be opened by the steering council rather than, say, me, so I opened python/steering-council#309 to ask the SC to open a poll. I hope they can do so before the SC elections