MaxTransferSize is by default set to 1 MB. At Microsoft IT we have found out that our storage arrays work with a lot less stress if MaxTransferSize is set to 256 KB. That is the recommended setting for many storage array vendors. We are currently going through this huge activity where backup jobs are being modified to add MaxTransferSize in there. If this were available as a SQL server wide option with sp_configure, it will make it so much easier for people to tweak it based upon what is appropriate for their environment.
Also, currently as per our conversation with SQL Dev, there is no way to specify MaxTransferSize for transaction log backups happening with LogShipping jobs and also any backup jobs happening via maintenance plans. Again, a server wide option would help resolve this.