This is a great one, thanks you so much
I'd just say one thing, it can be dangerous to open a forum to bots that is not allowed to guests, as is "showing different content to bots" than to guests.
Plus, the method used is technically cloaking, the result as well, Google can blacklist for this.
The bots features are impressive, but need a warning about this.
One could think without this forum auth feature, the bots mod is kind of a heavy method to get rid of SID (using as well cloaking method, but at least content stays the same) and I kind of agree in this case.
But there are more than search engine bots, such as boardtracker.com that could run different policies about this, I don't know, but it's for sure a problem with Google, thus with Search Engines (on day perhaps, Google won't be this important, but for now...).
Anyway, again and as always phpBB RuleZ, the best one ever.
With phpBB3, the phpBB group just nailed other BB to the carpet