Usb still has higher latency than firewire for midi controllers and monitoring effects in the DAW and Apple’s firewire to thunderbolt adapters allow firewire to still work on mac’s and even new thunderbolt windows laptops.
USB is fine but if you are playing keyboards and want the lowest latency then thunderbolt or firewire is better as it will give you lower latency at the same sized sample rate to USB.
I think my Apogee Duet was around 27ms and the Firewire tascam I had was lower at around 21ms at the same buffer setting so I guess that’s between a 3rd to a quarter lower latency. The Apogee seems fine though but if you want the lowest possible latency, firewire and thunderbolt interfaces are generally lower.