Both bikes you have considered are good for a beginner rider. The Honda CB350 H'ness will feel like a more spacious and larger machine than the Hunter, which will be a good thing if you are a larger rider. 

On the flip side, with its smaller size and 17-inch wheels, the Royal Enfield Hunter 350 will feel more agile and flickable in city traffic. Do bear in mind that coming from an Activa, both these bikes will feel quite heavy, weighing 181kg.

Something that will be similar to a ride but substantially lighter will be the TVS Ronin, which weighs 160kg. We recommend you take a look at the Ronin instead of the two 350s. Even though you are familiar with how to operate a clutch and change gears in a car, on a motorcycle, it is a different ballgame. 

Do take a test ride of the machines you shortlist before you decide. 

Both bikes that you have shortlisted will be excellent companions for your long daily run. Both the Honda CB350 and Royal Enfield Hunter 350 have smooth, torquey engines, upright seating ergonomics and a plush suspension setup. If you are a taller person, you may feel a little more comfortable on the CB350 because it is a larger machine than the Hunter, although the RE isn't exactly cramped. 

In a similar price range, you should also take a look at the Hero Xpulse 210. With its long-travel suspension, peppy engine and commanding ergonomics, this could possibly be the most comfortable bike to tackle long distances every day. Its seat height - at 830mm - is on the taller side, but if that's not a dealbreaker, we'd strongly recommend taking a look at it. 

A test ride of these three will help you decide which is the best option for you. 

The Harley-Davidson X440 will be a good starting point for a novice rider, although you will take some time to get used to its weight. Since you are shopping in this class of bike, other options to consider are Royal Enfield Hunter 350, Honda CB350 trio and the TVS Ronin. Of these, the Ronin will be the lightest and one of the most affordable options while still delivering comparable performance to the 350s. 

The Yamaha Aerox 155 is a good scooter in many ways, but its stiff rear suspension and cramped ergonomics for taller riders are two big reasons we would steer you away from it. If you do want a large-capacity scooter, then the TVS Ntorq 150 is our current pick because it has engaging performance but doesn't sacrifice comfort or practicality. 

Take a test ride of everything you consider, which will help you decide if you're ready to get into bikes or should stick with a scooter. 

Since you have already owned a Honda motorcycle in the past and are familiar with the ownership experience, the Honda CB350 makes for a logical step up. This is a smooth, comfortable, reliable and decently fuel-efficient machine which should serve you well over a long period of time. 

If you want to look outside the Honda umbrella, the Royal Enfield Hunter 350 is another great option to choose. The Hunter will feel lighter, more manageable, while retaining similar strong points to the CB350, like the torquey engine and comfortable ride quality. 

The Royal Enfield is also a good chunk more affordable than the Honda, which is something to consider, too. 

A test ride will help you decide which is better for you.