Since you already own a 150cc bike, it would make sense for you to stay in this same category. Of the options you have shortlisted, the Honda SP160 and Bajaj Pulsar N160 are the ones we'd recommend you go with. Both are smooth, comfortable, stylish and reliable bikes that will give you the fuel economy you desire when ridden sensibly. Another great option in this class you should take a look at is the TVS Apache RTR 160 4V. 

Make sure you take a test ride of these bikes to see which one suits you best. 

Since you already have a Unicorn, you could stick with Honda and get either a new Unicorn or its more stylish sibling, the SP160. Both are mechanically very similar, with the differences boiling down to features, seating ergonomics and a small price difference. These will return good fuel economy and also be reliable in the long run. It is an important thing to consider since your last bike is 17 years old. 

If you want to look elsewhere, bikes like the Bajaj Pulsar N160, TVS Apache RTR 160 4V and Yamaha FZ models are worth considering. Of these three, the FZ has the best fuel economy but is the least engaging to ride. The Pulsar and Apache have slightly lower fuel efficiency but offer you more comfort, power and features. 

A test ride should help you decide which is the right bike for you. 

If you want to stay in the same displacement range as your Unicorn, you can look at the Bajaj Pulsar N160 and the TVS Apache RTR 160 4V. Both have great suspension, peppy performance and will return similar fuel economy to your Unicorn. 

If you want to make a step up, then bikes like the Royal Enfield Hunter / Bullet / Classic 350, TVS Ronin, and Honda CB350 trio will make for good commuting partners. These are bikes with upright, neutral ergonomics, plush suspension setups and torquey, smooth engines. Expect lower fuel economy in comparison to your Unicorn, however, by virtue of its larger displacement.

Lastly, the Hero Xpulse 210 is a wonderful do-it-all machine which will have the best suspension comfort of all the bikes listed here.

A test ride of all of these bikes will help you determine which one is best for you.

In the 150-160cc commuter bike space, you have a good variety of options from different brands to choose from. Among the straightforward, simple commuter options, bikes like the Honda Unicorn / SP160 and Yamaha FZ models will be a good fit with their excellent fuel economy as well as comfortable ride and seating position. 

If you want something a little sportier, you could even consider the Bajaj Pulsar N160, which will also give you some features like a USD fork, which isn't found in most other bikes in the class. The TVS Apache RTR 160 4V is also a great option, but it can feel a little cramped, especially in the leg region. So we would recommend a test ride for all of these bikes before you decide. 

Since you have a longer commute, with its longer suspension and bigger wheels, a motorcycle will be more comfortable than a scooter, so we recommend going with a bike only. 

The 150/160cc commuter segment is a great one to be shopping in for city duties because it is packed with excellent products that are comfortable, decently powerful and quite fuel efficient. Bikes like the Bajaj Pulsar N160, TVS Apache RR 160 4V, Honda Unicorn / SP160 and the Yamaha FZ models would be our top recommendations in this class. 

The 350cc segment - while much larger - is geared to provide a more laidback, leisurely riding experience, and this is why you might think that these bikes "lack pickup." You should ask yourself what sort of riding experience you resonate with first before you start shortlisting vehicles. 

Some bikes in between these two segments that also warrant consideration are the TVS Ronin, Bajaj Pulsar N250, Honda CB300F and the TVS Apache RTR 200 4V.

A test ride of everything you're considering will help you decide. 

Depending on what sort of bike you want, there are many different options to choose from. If you want a sporty commuter, then bikes like the TVS Apache RTR 160 / 200 4V, Bajaj Pulsar N160 / N250, Honda CB300F and the Suzuki Gixxer models will be good options to consider. 

If you want a neo-retro bike, then bikes like the Royal Enfield Hunter / Bullet 350, Yamaha XSR155 and TVS Ronin will be the ones we recommend. 

If you want an ADV, then the Hero Xpulse 200 / 210 will be bikes that deserve your attention. 

Take a test ride of everything you shortlist before making a decision. 

In the 150/160cc category, your best bets for a comfortable and fuel-efficient machine would range between the Honda Unicorn / SP160, Bajaj Pulsar N160, TVS Apache RTR 160 4V and Hero Xtreme 160R 4V. 

Depending on your physique, each bike will fit you differently. So, we would recommend a test ride of all bikes on both good and bad roads before you make a purchase.