Per this document, Quad-Sup is now supported in the Catalyst 4500.https://www.cisco.com/c/en/us/support/docs/switches/catalyst-4500-series-switches/118597-config-vss-00.html

ipsec tunnel throughput still limited to only 85Mbps unless additional FL-4330-HSEC-K9 license is purchased? Yes, security and performance license are two different things. or does it also increase to 300Mbps? No If hsec is required, is it necessa...

Finally Cisco added support for front-back airflow for the 5596T on the NX-OS Release 6.02http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5500/sw/release/notes/6_02/Nexus5500_Release_Notes_6_02.htmlCisco Nexus 1100 W AC front-to-back po...