Plenty of benefits, number one in my mind being the ability to upgrade to the latest version of Android MUCH sooner than waiting for your manufacturer to release an upgrade.

The only real con is you'll void your warranty. If that's not a concern for you then I say go for it.

Just as a side note, I have not rooted my Droid yet because of the warranty issue. My workplace is ridiculously hard on phones and I'm positive this one won't make it past the warranty expiration date alive...