Jumbo Frames with em

I'm running -current on a NFS file server with a 3ware controller
striping across multiple disks.  The box uses the em driver with the
mtu set to 8192 - client machines connecting via NFS that are also
running -current with bge drivers with the mtu set to 8192 (and jumbo
frames enabled on the switch)...

The em driver's README says that UDP and Jumbo Frames don't play well
together - just wondering if this would have any impact on NFS over
TCP?  Does anyone know anything about the future of the em driver or
bge driver that might have performance issues with Jumbo Frames?

I'm only ever seeing the storage system write about 10 to 15MB (bytes)
per second over NFS.

This environment hasn't gone production yet, so I can do any testing
or benchmarking if anyone's interested....

Thanks,

D