fs1::~> du -sch /data/downloads/Linux/mirrors/gentoo/
38G /data/downloads/Linux/mirrors/gentoo
That was my fix for downloading things and speeding up the install. Took me about two good days, not the whole 48 hours though, to rsync the gentoo tree. And if you run an rsync every night or multiple times a day the number of things to downloads isn't a lot, maybe a few updated packages in the distfiles area. In your make.conf file just point to your local server
ftp://mymachine/blah and you are downloading packages average 9 MB/sec. Which really helps out a lot when you are doing this on multiple machines or doing it over and over again for fun