afelix / YouTube Aspect Ratio Control

Your @include appears to be exactly identical in functionality to

// @match *://www.youtube.com/*

As a general rule, @match is more reliable and performant than using include regex. It's less likely to break, seeing as it's a part of the Chrome addon specification (and the newer WebExtensions spefication). It's also more widely supported on different UserScript engines. There have even been talks of removing the regex feature of @include.

You can read more about match patterns here.

Re: @BigTSDMB:

As a general rule, @match is more reliable and performant than using include regex.

This is false. Most engines, and browsers, that support regular expressions (re's) convert patterned globs, such as @match to regular expressions. So reducing an extra set of conversions is an improvement. @match is less "performant" since it has a stricter pattern.

It's less likely to break, seeing as it's a part of the Chrome addon specification (and the newer WebExtensions spefication)

In order of effectiveness... re's, generic globs, and then specific glob matches. So it's a good idea to include all three if one is that paranoid about breakage between the different engines and browsers (including versions).

It's also more widely supported on different UserScript engines.

Untrue with @match throughout the history of Userscripts.

There have even been talks of removing the regex feature of @include.

This part may be true on the Fx side since the Fx development team is getting rather lazy these days.