What was slow about it? Depending on how you use template binding, it should be as fast as anything else.

It's possible he was using Polymer v1, which was pretty slow.

Polymer v2 in a web browser that supports Web Components v1 should be pretty fast, though. But that was only released last May.

It was very slow to first paint around 1.0 which made me use something else. But it's become so much faster since then.