Some new nice features in this release.
By the way although my.x-cart.com shows for days now there is new version coming I have nothing in my dev store and resources page for 5.2.7. So there is some sort of time discrepancies (and yes I have the option developer checked in admin).
Also about the admin directory change - you should make it clear and discourage the use of name which suggests "admin" or not to have it in the robots.txt. robots.txt file is public and can be seen by anyone - example -
http://www.x-cart.com/robots.txt