When we turn on RBS with a content database that has Shredded Storage enabled, the real-time RBS provider receives each shredded BLOB individually. These shreds are extremely small, storing BLOBs outside of the SQL database that are less than 1Mb is, in general, inefficient. This is why we recommend setting up RBS rules that leave files less than 1Mb in the content database.
some scheduled RBS product (DocAve Storage Manager) will work fine with Shredded Storage, as when Storage Manager calls SharePoint to externalize it we do get the full BLOB. We can also do more sophisticated business rules to decide whether we externalize it with RBS also.
By adding the RBS Provider into the mix, when I’m fetching the 69th version of a document, it’s going to get REAL chatty with the RBS provider fetching all the individual shreds. The shred size can potentially be changed up to 1Mb to be more efficient from an RBS perspective, but until we get more data from our labs we have no concrete guidance here yet.