I've updated the original post at the top to include the new location for our Visio stencils - they're on our main website.
We've also updated the SummitX and IdentiFi stencil sets to include a few more products, new and old.
You can find them all here:
http://www.extremenetworks.com/support/visio-stencils
SummitX now includes X430, X450-G2, and X670-G2. IdentiFi now includes the C35 Controller and AP3825 stencils.
The new location is also described in
this GTAC Knowledge article.