Does not support Clientless SSL Does support Clientless SSL
Only supports AnyConnect client connections Supports all flavours of SSL VPN, including:clientless SSL VPN, AnyConnect client VPN
The OS of the ASA has a software switch in the VPN config that only allows for the ASA to be in one scheme or the other at any one time so you cannot have both and Essentials and Premium license active at the same time.
Julio Carvajal Senior Network Security and Core Specialist CCIE #42930, 2xCCNP, JNCIP-SEC
As Julio said, only one of the licenses can be active. If you only need 10 clientless sessions and many AnyConnect-sessions without hostscan or CSD, then it could be cheaper to buy another ASA just for the clientless VPNs and install the Essentials on your actual ASA.