i pointed to this library because it is present in npm, you can add it with CDN,
a full documentation is available plus you have the support and it is widely used by a lot of other projects even in bitcointalk. it is just objects, and requires a minimal amount functions unless you want to do some bright effects.
that we use such libraries on daily basis.We only use open source stuff and trust me,the options d3.js or velocity has to offer
can pretty much get you all you can get from a paid project.
However,it's a personal opinion.
I had a look at d3.js, but it looks like tricky on some points, however i never had a deep look into it, do you have a fiddle ?
For Velocity, i never heard about, do you have a fiddle ?
Sorry if i disturb you, but i am curious.