the Twitter logo can be create in basically 2 path elements.
What if my logo is much more complex? Is there a threshold at the complexity of my image results in an SVG payload > than a properly compressed raster image?
Logos especially are generally by nature clean and simple to be able to quickly communicate brand through different mediums.
From a practical sense, I'd be hard pressed to find a real logo/icon that wasn't better in SVG. Theoretically, of course there are limits, but the rule of thumb is strong: always use svg for logos and icons.
Not bad
It's a bit of a silly way to do it - and is probably more complex to render.
I would guess, though, that if you make a logo that is larger as an SVG than a compressed raster, you’ve probably made a bad logo. Logos should be simple.
Agreed. Simple but important things to also consider with Logos include "What does it look like if printed in black and white?" It's a bit outdated advice in some regards, based as much on letter headers, fax machines, and news print adverts, as anything else. You'll notice that almost all memorable logos work really well in black and white, though.
Is there a way to quantify simplicity in terms of SVG? Can we say number of points & number of paths? What other constructs can be used to measure complexity?
File size after rendering to bitmap and lossy compression, like JPEG, might actually be one of the best quantitative proxies for simplicity, because lossy compression algorithms are designed to compress visual data that's interesting to humans well. Maybe an interesting experiment: take a whole bunch of logos and/or other images, let people rate them on a Likert scale or something on simplicity, and see if there's a correlation with JPEG file size.
I draw comics in Illustrator, and I have created files that are larger than the corresponding 300dpi TIFF. I think the first page in http://egypt.urnash.com/rita/chapter/viii/ is one of them, that dense setting at the bottom is super complicated.
(And it's a TON larger if I save the file as a pdf, Illustrator is doing a lot of high level abstraction to make this file smaller, that I’m not sure if SVG can handle.)