If what they do to brown rice is anything like what's done
to white rice, then it is "pre-cooked", like blanching,
steaming, etc . . . then it is dehydrated and packaged
for your convenience.
You rehydrate it, cook it in less time because of the
above process.
The advantage is a faster cooking time.
The disadvantage is they pour off the liquid that was
cooked in (like pot liquor) so you lose some of the protein,
carbos, and calories and some vitamins and minerals. But
it is not uncommon for some vitamins and minerals to be
put back in (fortified). Plus it cost more.
My opinion, stick with the original unless you are absolutely
pressed for time. Tastes better too.