First, let me just say I really enjoyed GUADEC in Denver. You all did an excellent job, I loved the venue, the city, and spending time with so many awesome people 
I also appreciated the specific mention of the COVID policy at the event, and I agree the venue - all the rooms, including for BoFs - worked well for the hybrid setup.
One thing I love about a conference like GUADEC is its ability to break down cliques and bubbles; encouraging people to engage with areas of the project they wouldn’t otherwise engage with. I was talking about this with people who focus more on the community and governance end of GNOME. Despite the occasional inconvenience, I like it when a conference schedule nudges attendees into tracks they wouldn’t usually pay attention to (or feel welcome in). It’s that type of movement which helps a community to learn and grow.
With that in mind, hybrid GUADEC scares me just a little bit because it presents an opportunity for bubbles and cliquiness to grow. Both in the way people interact with remote events, and in the way parts of the community can become geographically isolated.
That isn’t a reason not to do it at all, but I think it’s really important to be thoughtful about it.
I appreciated having good quality AV for all the remote interactions with folks in Berlin. But I don’t think it’s a good thing that we do the same mini GUADEC every year. I think the Berlin event is amazing, I hope to attend some day if I ever end up nearby at the same time, and I think it should keep happening every year for as long as the organizers can do it. But I think it should be decoupled from GUADEC at least half of the time. If we want this mini GUADEC + big GUADEC thing to work, we need to do it in a way that it isn’t the same people every time who are close to the mini event. Importantly, this means that different people should have the opportunity to attend a closer-to-home event each year.
For a future North America GUADEC, it would be interesting if we had a way to guesstimate ahead of time about the climate impact of an event on the west coast or east coast. (Or does that happen and I just didn’t notice?). For instance, I don’t know if there’s anyone local here with event planning experience, but I’d be interested to look into the options for a big or mini GUADEC in Vancouver. However, I’m unsure if that would be a reasonable flying destination for a big enough chunk of the community, and maybe I need to bug some Montreal people instead.