RabbitMQ Active/Active

The following documentation states that it may be best not to use RabbitMQ active /active mirror queues, even tho it is favored by the RabbitMQ community.

http://docs.openstack.org/trunk/openstack-ha/content/s-rabbitmq.html

I would be very interested in hearing from anyone that can help with the following,

1) Understanding if this is still the case?
2) What their experience has being with active/active RabbitMQ active /active mirror queue?
3) Where the instabilities may be?
4) Any other potential problems with active/active RabbitMQ active /active mirror queue?

Thanks all in the community.