As for jumbo frames, will someone remind me what the benefit of using a larger MTU on the edges than you have in the core is? Is the edge device going to aggregate 6 1500-byte packets into a single 9000-byte jumbo frame for me?

It's an internal LAN system issue on the edge. In a distributed system environment, having app servers talk to data servers, using jumbo packets, makes for higher system throughput. The Jumbo packets should never be seen at the border, however. In fact, the data servers themselves should never be seen fromn the border <g>.