I started a Vortex comparison sheet a couple of years ago, but abandoned the project.
I still have some of the data, but not much.
A small Vortex held 80 briquettes, a medium held 110 briquettes, and the large held 124. In comparison, a large Weber Chimney held 100.
I don't remember what brand, but I think that the briquettes were Kingsord Competition.
I regularly use a GBS grate with my Vortex, but I haven't tried the large size yet. I think that I will try it and see if it gets any hotter.