I’m 35 years old and 5′10″ tall. I’ve been using a Honda Hornet CB160 (original launch version) for 10 years. I have a daily commute of 30-40 km with an equal mix of highway and rough roads. I’m…

Since you have had a good experience with your Honda Hornet, you could stick with the same brand and step up to any of the Honda CB350 models. All are mechanically very similar, and picking between the three comes down largely to which one you prefer the look of, as well as pricing. All three are comfortable, torquey, well-finished and decently fuel-efficient machines. 

If you want to switch things up, Royal Enfield has three 350cc machines which deserve your attention – Hunter, Bullet and Classic. The Hunter is the lightest and most agile machine of these three and will feel the smallest, too. 

The Bullet and Classic are considerably heavier and have commanding riding positions and great suspension. 

A test ride of all these 350s should help you decide which is the best option for you.