It does make it a bit trickier to automate, I had to split my build script into two halves, but as said above a lot less mucking about with adjusting the tool chain.
Also the tarball for the finished tools ( if you dont archive the source's ) is a few 10's of M smaller.
But switching into chroot half way is I think going to cause some problems for some newb's ( RTFM!
).