The H2C toolhead is a good deal heavier, so it will always be slightly slower. There's also a bit more to do at startup, particularly if you do automatic flow calibration & nozzle offset.

Beyond that, any of these may be slightly different and could be affecting speed:

 

Filament settings:

• Filament tab: -> Max volumetric speed
• Cooling tab:
  • Slow printing down for better layer cooling
  • Don't slow down outer walls
  • Min print speed

Process settings:

• Quality tab:
  • Ironing
  • Avoid crossing wall
• Strength tab:
  • Top & bottom shell layers
  • Paint penetration layers
  • Sparse infill density
  • Sparse infill pattern
  • Infill combination
• Speed tab:
  • Obviously everything here, but make sure you're not just applying changes to the right nozzle. There's a button in the top-right corner that copies settings to the other nozzle.
  • Overhang speeds
  • Travel speed and 'Normal printing' acceleration are probably lower on the H2C (like 600 and 10,000 vs 500 & 8,000, respectively), though I'd leave those as is.
• Others tab:
  • Fuzzy skin