[Farling]

For me, the main benefit of HL was that it would dynamically update all the stats when a character received a buff or debuff. The added benefit to this for HLO is that a group buff can (in the future?) be applied as a single action, rather than having to edit each character individually.

When GMing, I've always run the monsters from within HL, never using whatever map system is being used for live or online play; for the same reasons, that PCs can debuff monsters and all the stats will be updated live.

For me, Integration of HLO with a VTT would allow the HP to be displayed on the character's token (effectively providing a health bar for other players to see the party member's health).