Compared to Visual Assist it may not have all the bells and whistles yes, but especially the code navigation (which to me is the most important aspect) and code completion is quite advanced already and incredibly fast, even compared to Visual Assist. Parsing the entire UE4 codebase for the first time (in the background) takes a couple of minutes. Opening it from cache is practically instant, all search operations / code completion are also near instant with no stalls whatsoever. In terms of refactoring it is more limited, but renaming symbols works well and that covers about 99% of the cases were I regularly use refactoring tools anyway.
And unlike Visual Studio or JetBrains IDEs, 10x is so fast and lightweight that I would like to use it for all of my text editing needs. That makes customizing it much more satisfying as well, which is quite easy to do with a straightforward Python API.
As you can probably tell I really love this editor, it has had a quite dramatic impact on my enjoyment of work already. It won't be for everybody (and it doesn't try to), but I would encourage everybody to give it a try. If it is the kind of editor you are looking for, I think you will be very happy with it.
Using an editorconfig file I never had an issue doing this. I get a tab if I hit tab and a space if I hit space.
Firstly, on speed, I really recommend giving it a try. There's things like launch time / time to syntax highlighting which are nice to have and make it a joy to use but then there's things like instant 'Find References' and workspace search that I think contribute to a qualitative difference to the way I work - I simply would not use these features as much or in the same way if they took seconds (as they do in VS).
Seen some discussion comparing to things like Sublime - 10x understands c++ code much much better than sublime and that's crucial for making some of its best features like 'Rename' and 'Find references' work so well.
The other thing I think is worth mentioning is just how active and responsive the developer is. Bug-fixes and improvements often get implemented within hours of reporting. As an example, I've always been annoyed by how impossible it is to make VS do 'tabs for indentation, spaces for alignment' - after a brief discussion, this got sorted in 10x quickly. I think that's a serious advantage over Visual Studio, that often has annoying issues/bugs languishing for literally years.