We just got a shipment from SWF.com on thursday. In Jan the rock smelled good when it came out of the box, this week it stunk. Must be a difference in the temp outside. It had a lot of die off this time. We are cycling out tank with it so it is okay, but the den smells funky!
For my tanks that are up and running I buy additional rock from the LFS with corals growing on them. This was the plan all along so I left room for additional rock.
If you are just starting your tank, the rock online is far cheaper than at the LFS. If you are up and running then you will need to cure it for atleast two weeks in a seperate container. HTH