From my understanding,
The SVGZ is a compressed file type of an SVG. I love using SVG images and have had a lot of experience with them.
All of the times I used them I have never had a graphic that went over a few hundred kilobytes.
I use SVG for responsive graphics while making responsive websites. I also use them since my favorite design style is vector based graphics. My strongest design strength is illustrator, especially when it comes to graphic design.
The other reason I would use an SVG graphic is due to the ease of animating certain elements of the graphic, like arms, legs, etc.
Especially background elements, like a city to span across the entire page while I animate some flickering of lights and so on.
If the file is compressed, would it lose the SVG code so I couldn't animate it?
Is there any reason I should use an SVGZ over just an SVG?
Well I decided to just make an SVG and SVGZ to see how they acted with the web since I found out my works ancient CS3 can save SVGZ!
After testing I ran into a very unexpected problem with the SVGZ file type. (Tested on Chrome, Firefox, and IE) If you go to the direct URL of the image you get an error. I am assuming you can't access the SVG code on these files types but after making a fiddle it doesn't even seem to display the image.
Are these useless for the web?