Buy 125cc or 150cc???

[Alwaroullace]

Wondering between 2 types of engine capacity (not convenient to name the car to avoid trouble).

I just run around the inner city, morning to do the evening walk, sometimes climbing mountain ranges 15 degrees to go play.

So what kind? The economy is enough to buy more powerful but only enough not to have to think too much balance should be very careful. There are many differences.

Thanks everyone.