lucy24 - 5:13 am on Feb 28, 2013 (gmt 0)
This may just be me, but rules involving long strings of [OR] conditions make me nervous. If the options are too long to fit in a single pipe-delimited list, handle them a different way.
Oh, and your entire rule would fail disastrously because you've got an opening anchor on every single User-Agent. Few robots are thoughtful enough to put their most important element right at the beginning.