We don't have a lot of devices, but I would say that no, we're not 100% organized here in regards to SNMP traffic. I'm not even sure how much is too much to be honest, but so far with several admins running network inventory/discovery polls in half a dozen different packages, we haven't had any issues yet.
At some point, I'd like to get around to tracking just how much traffic is being generated but considering the size of our network it really hasn't become an issue yet.