I have splender plus 2007 model and it has been 10 years since than, and my bike still in good condition and easily picks the speed of 60-70 km per hour. If you take care of this bike, its life line can easily cross the 15- 20 years threshold.
Only disadvantage I found in this bike that it creates a sound when you are riding this bike in steep roads but its milege is extraordinary in every aspects.
Its total weight is approx 110 kg and height of bike is comparably low, so you can easily make balance when you encounter any slippery or difficult situation.
Due to these qualities it is one of the most used bike in India.