The main differences are:
Fllo is less expensive than the Foonf
Fllo offers a flexible LATCH instead of the Rigid-LATCH on the Foonf. A flexible LATCH is typically easier to install in a wider range of cars. You can opt to use the seat-belt installation method for both seats.
Fllo is 25lbs. and Foonf is 33lbs.
Foonf has more advanced energy absorption technology built into the base.
Foonf has an easier recline trigger to change positions. Fllo’s angle is adjusted through manual repositioning.
Foonf is taller than the Fllo by about 1.5-2 inches.
Both convertible car seats have the same weight and usage limits, and the seats are the same widths at 17 inches. You can use both seats 3 across in most vehicles.