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.

