Wired Intelligent Edge

It seems that aruba is moving towards vsx as the main HA technology, is this correct ? 

unfortunately at the moment its a bit confusing to choose a good & flexible core switching for medium sized businesses... The 8320 seems the best fit, as it supports vsx  and has options for 1/10G SFP+ as well as 1/10G base-T and 40G. The downside is that these are not stackable ...so each 'peer' of the vsx is limited in this sense. 

The 5406 is limited in other aspects such as type of 10G modules and supports only vsx ...

then there is the 8400 of course, but this is way too expensive and an overkill for medium sized campus LANs 

the 8400 also seems to have limited tyoes of Line cards available (at least for the moment..)

There is still also option for HP IRF switching but it seems these are slowly being put to the side and most don't seem to fit the 'core' function ...also upgrading IRFs might be more difficult then vsx..

maybe HP/Aruba could provide us with an updated chart of core/distribution switch comparisions and way forward as the only ones I found are a bit old and not comprehensive....

Aruba VSX shares only Ethernet Switching planes, Management, Control and Routing planes are just kept synchronized by means of VSX deamon running on Aruba 8320 (or Aruba 8400) Primary node on a two nodes Aruba 8320 (or Aruba 8400). See it like a Distributed Trunking on steroids. Aruba VSX has VSX ISL Inter-Switch Link and VSX Keepalive link (to mitigate Split Brain condition). Initial Multi-Chassis LAGs - MC-LAGs - are now called VSX LAGs and southbounds and northbounds connections to non-VSX solutions (so to VSF, IRF deployments or to single standalone Switches) are just realized on those devices against VSX LAGs using standard LACP IEEE 802.3ad aggregated links (distributed to both VSX nodes simmetrically).

Aruba VSF is a Virtual Switching technology that let you to have a single (virtual) Management plane...that far more similar to HPE FlexNetwork IRF than to Aruba VSX even if HPE IRF is - in my opinion - more evoluted (and with a very long history/heritage) than recent Aruba VSF (think about IRF ISSU procedure versus VSF Fast-Software-Update).