Hi @danmoyle ! Great question.
For starters, everything in help desk is a ticket, regardless of channel (including chats!), which really streamlines the overall experience. In inbox, some things were conversations, and some were conversations + tickets—this made it more difficult to set up things like workflows and reports. The majority of our customers also struggled with keeping things like owner and status “in sync” across the conversations and tickets objects, so the new, ticket-centric model of help desk is much easier to manage.
Help desk also contains a bunch of functionality that you can’t find in inbox. There’s a list-style view of tickets (similar to object index pages), which allows you to get a better at-a-glance view of many tickets, something we know our customers struggled to do in inbox. Custom views, sorting, and filtering across tickets is more advanced. Help desk also contains exclusive new functionality like more advanced SLAs (i.e. set SLA based on ticket team, pipeline, priority, etc) and skill-based routing!