While I’m also in the “Meteor is great as is” camp, I think it’s also good to keep in mind there might be some survivorship bias here in the forums.
This weekend I visited Q42, which a couple years ago was one of the biggest dev firms in the Netherlands using Meteor. Back then, they were also actively advocating Meteor, organising meetups, writing blog posts, and contributing to the framework. I was quite surprised this weekend when I mentioned Meteor, I got a response along the lines of “oh, Meteor, hah yeah that’s dead”.
Apparently they did run into some serious scaling issues on several projects, that were “impossible to fix” (I don’t know the technical details), and that eventually forced them through a very painful process of extracting Meteor from those apps. Needless to say, they won’t come anywhere near Meteor again.
Unfortunately, these people are not coming to this forum anymore to tell us about their experience. But I think given their experience and knowledge they would be a very interesting party for Tiny to give a call. Again, I don’t know the details, but this was a company that was very invested in Meteor on multiple levels, with great engineers, that was not able to get it to scale for some reason. That is definitely something that needs addressing, or at least investigating.