I have played around with using SVG effects as they are stunningly powerful, but I wouldn't recommend deploying them for too much: even though apparently Firefox does some level of GPU acceleration for SVG filter graphs, in practice a lot of very simple looking graphs I've tried constructing seem to fall back to CPU even with webrender.all turned on. This is kind of a shame because feTurbulence in particular is pretty useful. You could use it for a lot of things. One case I wanted to use it for was to make a gradient grainier, to reduce the obvious banding. Unfortunately, I found that it pegs all of the CPU cores on my laptop immediately :)
WebRender unfortunately doesn't handle vector content at all, so all vector content in Firefox is rendered using CPU (CPU part of Skia). This is not true of other browsers.
I think SVG filters are actually all raster effects, which is why WebRender supposedly can accelerate SVG filters... though if it does, I seem to be hitting cases that force it to fall back. Maybe it doesn't like SMIL animations.
It's a shame that modern browsers don't optimize SVG to be processed in the GPU. It has plenty of potential, not only feTurbulence, but many other effects as well. And being able to use SVG masks on standard HTML elements would also open a bunch of creative opportunities.
Unfortunately, as you say, it's very easy to freeze a GPU if you start doing more complex SVGs.
