I bought this scooter 2 weeks back so cant actually give you the review for fuel consumption, but I can say that the scooter has following pros:
-Comfortable seat.
-Good handling.
-Low fuel indicator.
-Large foot space ( you can place an LPG cylinder).
If you ideal run the scooter more than 30secs the power light starts blinking indicating you should turn off the scooter to save the fuel (there are two lights on is green for economy and other is yellow for power. If you drive under 50 green is on if you go up then yellow comes on it helps in maintaining the safe speed and get good mileage).
-Tubeless tyres on alloy wheels 12"
-Outer fuel cap
-Pass light switch
-Starts without any trouble
-As far as hill roads are concerned I havent checked it yet but I bet it will perform nicely.
Cons:
-Disk brakes not present
-Looks are like its name (rear end is too wide)
since I havent checked the mileage till then 3 stars. Overall the TVS Jupiter is the one you should go for.