Interestingly WebGL is way slower than SVG and Canvas in this case (Chrome, rMBP): https://jonobr1.github.io/two.js/examples/particle-sandbox.h...
I'm currently developing a way to "cache" textures that don't change much so if you had a Two.Group that doesn't change much you can turn that into 1 texture. This will greatly increase performance as well. Thanks for checking it out!
#themoreyouknow