I have a Agility City 125. Not a bad scooter, but you do feel it's a bit underpowered at times. Haven't rode a 200+, just sat on if a bit at the dealer.
The 16+ 125 is basically a 16+ 200 with a 125ccm engine. No significant difference in power between the carb and FI 125.
As you already probably know the main differences between a Agility City 125 and a 16+ 200 is engine displacement 125ccm v 163ccm,power
9.5hp v 11.5hp, carburetor v fuel injection.
Front wheel on the 16+ 200 is 16",rear 14", on the City 125 they are both 16"
Fuel tank on the 16+ is underneath the scoot and the filler is on the front left side. Because of this there is some more room under the seat, but not too much.
The fuel tank on the Agility 125 is under the seat limiting the already small space.
If it's in your budget limit I would go with the 16+ 200, more power, similar fuel consumption, and fuel injection.