Since you own a KTM 390 Duke and have spoken about its performance, we'll put that parameter at the forefront when recommending some options. The Kawasaki Z650, while a quick, light and premium machine, can feel a little dull if you're stepping up from the fast KTM. While the Honda CB / CBR 650 models are now knocking on the door of 100hp, they are also quite heavy machines, and the engine is rather peaky, which means that you'll really have to work for the performance. 

In the Honda lineup, we suggest you look at the CB750 Hornet, as that is a punchy and lightweight machine that will feel like a good step up from the 390 Duke. 

You can also take a look at the Suzuki GSX-8R because even though its spec sheet is quite modest, in the real world, this is a very fun machine that doesn't sacrifice practicality too much. Another option in the same segment is the Triumph Daytona 660, which is also a relaxed, real-world usable sportbike with engaging performance. 

If you want to break the 100hp barrier well and truly, bikes like the Triumph Street Triple R and Kawasaki Z900 are the most affordable options. The former is an accomplished track machine, while the latter will be a sublime road bike owing to its creamy smooth engine and plush suspension.

We recommend a thorough test ride of all bikes before you choose to go ahead.