If you follows -Current tree, then you must be ready to update lots of thing when new batch comes out as it may contain huge changes from previous one. One simple way to keep your mirror or local repository up-to-date with the tree is by the use of rsync. AlienBOB has written several scripts and one of them can be used to set up a repository of the -Current tree using Rsync. All you need to do is set up your local directory and point to the nearest mirror on your location and execute the script.
Since almost all of the packages have been converted to .txz formats, i used this script to download them all and put them on my local repository. Very easy to setup and the main point is that it works