Looking out for performance with an eye on the fuel consumption? By performance here I dont mean a good mileage. Thats covered in the later part of the question. Its the feel. I am using this machine for last 6 years, its still running as it used to when I bought it.
What I like about the bike is its the smallest in the market. Its the lightest too. Just 110 kgs for 135cc. Thats gr8. Few might agree to this point that lesser weight is better. But let me tell u a fact - Most of us would be using the bike in a metropolitan ambience, crowded, traffic, signals. Maneuvering the bike is really easy and efficient. On highways the machine can run @ 105 kmph. Thats what I had drove upto.
Another feature I find is the gear system - one down and three up. The bike used to be four geared, the model available now comes with five gears, thats one down and four up. The most important way of controling a bike is by using the gears efficiently. Moving to lower gears in order to reduce speed (in case of braking) should be more convenient than switching to upper gears. Any wise biker would tell you to use your gears efficiently with your brakes to control the bike.
Look at the pickup of the bike. Of course is lesser than the higher end bikes, but its amazing at the mileage its offering, thats in the range of 40 to 45 kmph. Moreover look at the price - less than Rs. 50000 (even lesser now). Compare it with other bikes in all respect. Other bikes pack the offer with some small complements like, two meters one for kmph and rpm. Some even provide a side stand indicator. But for sure not at this price and performance.
To add a topping, it can also start with a kick just by pressing the clutch on any gear unlike conventional bike where you have to move down to neutral and kick. Some might tell you that doing so would affect the bikes performance, but believe me its six years now and no issues. And by default when you talk about Yamaha, its zero maintenance by default. Dont go by the actual meaning of it ;) So its all YES for the YAMAHA RX 135