Two Dolphins use different filtration systems. Premier has multiple filter options, which include bottom-load fine cartridge filters, ultra-fine cartridge filters, and an oversized fine filter bag. The Quantum uses a top-load basket for fine and ultra-fine filtration.
Plus, there is a difference in navigation. While Premier runs with CleverClean navigation for scanning and route planning, Dolphin Quantum still boasts of SmartNav 2.0 mapping navigation.
And the last difference is the cleaning cycle, where Premier works for 3 hours in a Standard mode, and the Quantum needs 2 hours to perform the cleaning.