I was driving a scooter, 50ccm since i am 14, back at that age they were awesome  
And yeah, stock, they are good, if you do not have any alternative (at least they go with petrol and look cool), but if you get your hadn oily, change vario, maybe bigger piston.. 
If you change the vario, they can be awesome, but changing the piston is illegal, so never ever do it, we did not do it as well.....  
  
I was looking for a Rs 125 for quiet a time, but my problem is that the bike is twice he price of the car, and it is always rainy here, and I cannot transfer my bike with it.. but if it would be a warmer country, or less rainy, I would get a mito/rs125 in no time