Do browsers handle these the same?
Yes, all (modern) browsers handle these the same. In that all (modern) browsers implicitly URL encode (ie. percent-encode) the URL if you don't explicitly encode this yourself in the HTML source.
In both cases, the browser will implicitly request the percent-encoded URL when a user clicks the link. Select "Copy link address" from the browser's context menu and you copy the percent-encoded URL in both cases. Reading the
In fact, I believe HTML5 allows unencoded unicode characters:
A potential problem might just be "old browsers". How old I don't know. But "old" might just be too old to worry about. (?)