I think this isn’t just a matter of personal preference, but it’s also largely a cultural thing – in German, for example, the “space-en-dash-space” form is common.
This is true for a lot of other punctuation as well. For instance, in Germany, we quote „like this“ instead of “like this”. Whereas in Switzerland or France, it’s common to quote using Guillemets, as in «Hello there!». This style can also be found in German texts, though it’s less common than quotation marks, and it would typically be used »inversely«.