I try to push the limits of WebGL, I'm using almost everything there is, plenty of extensions (bear in mind these are not really exotic features, most are supported by majority of GPUs out there, native desktop games use much wider set of capabilities, it's just that WebGL implementations are only exposing them slowly).

In general Chrome has the most complete WebGL implementation, though Firefox does seem to be catching up recently (they do push for WebGL 2 so some features are popping up in WebGL 1 as extensions, but for example Firefox uses much older version of ANGLE and also no DX11 ANGLE in sight there, so on Windows Firefox is still quite behind Chrome).

IE11 WebGL on the other hand has troubles even just with basic WebGL specs, it still has broken and not implemented features, not even speaking about majority of extensions.