I can't imagine any reason why the old RecentChanges should be favoured. It's ok only for few people who are not scared for instance by a page cluttered with hundreds of edits to a particularly active page of the moment, and so on (see e.g. bug 33461 which complains about what's actually a very standard problem of the RC).
Actually, the only reason may be that not everyone has JavaScript. I doubt this is a problem nowadays, and even without JS the enhanced version is good (better than the normal one), anyway the other would be kept as a preference (compare bug 22114 which asked removal).
Version: unspecified
Severity: enhancement
Whiteboard: design-wished
URL: http://article.gmane.org/gmane.science.linguistics.wikipedia.technical/60474
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=59487