D&D 5E Square grid, what's the difference between a square and a circle?

[Hussar]

I suppose, for me, the fact that I play pretty much exclusively on a VTT and have for years means that grid doesn't bother me in the slightest. I've been playing on grids since even before 3e - Star Frontiers, for example, and the James Bond RPG both used grids. So anything that makes grids easier to use is an improvement in my book.