KTM 250 Duke

The KTM 250 Duke you are considering makes for a great one-bike garage to handle city and highway duties both. It has a punchy - yet not overwhelming - amount of grunt, engaging handling and will also return good fuel economy. 

Coming to the Triumph Speed T4, depending on how you ride, you should see decent fuel economy even inside city traffic. Since the bike is made by Bajaj, it shouldn't be too expensive to maintain. The advantage of the Speed T4 over the Duke will be its more effortless performance and more comfortable seating and suspension. 

And since you are shopping in this space, the TVS Apache RTR 310 is also worth taking a look at. The RTR 310 is a feature-rich machine with good performance and handling. Also, we will recommend you get the variant with the quickshifter as it is still priced sensibly, and this feature will enhance the riding experience. 

Since these are different machines in the riding experience they deliver, we'd recommend a test ride of all three before you decide. 

Since most of your usage is inside the city, bikes like the Hero Xpulse 210, Royal Enfield Bullet / Classic / Hunter 350, Honda CB350 trio and the TVS Ronin will make for good options to consider depending on your preference. 

If you do want something a touch sportier but not very rambunctious, then the KTM 250 Duke also makes for a great companion. 

A test ride of everything you decide to shortlist will help you make a decision. 

Of the three bikes you're considering, the KTM 250 Duke will be the most engaging handler, but it has the least peak output and the smallest engine. This means you will have to rev it more to access the meat of the performance.

The Triumph Speed 400 is the most powerful bike of your shortlisted options. It will be a great city bike because of its effortless performance and plush suspension.

The TVS Apache RTX 300 is sure to be the most comfortable machine of the three. Its long-travel suspension and commanding ergonomics help, but it is also the tallest and heaviest bike on your list.

Take a test ride of all three to see which one fits your needs the best.

If you are comfortable with the size and heft of the TVS Apache RTX 300, then it is certainly worth considering because it will fit your needs quite well. 

If you want something in the same price range that is lighter and more manageable, then bikes like the Bajaj Pulsar NS400Z and the KTM 250 Duke are worth considering. 

Take exhaustive test rides of all the machines you shortlist before you decide. 

Given that you want something manageable and this will be your first bike, here are a few options we recommend.

The Honda CB300F and CB300R are both lightweight, well-built, and have low seat heights. You could also check out the KTM 250 Duke or the Husqvarna Vitpilen 250. Both are mechanically identical, but they differ in styling and riding posture, the Vitpilen has a slightly taller seat than the Duke.

All these are fun and entertaining first bike with a reasonable performance ceiling to keep you interested for a long time.