This is very much a personal choice question. The iPad Pro 9.7" is not a laptop with a desktop operating system, in spite of what Phil Schiller, Apple's head of marketing would like people to believe. Nor, is it an iPhone. The iPad Pro 9.7" is a standard sized tablet with an operating system optimized for running single purpose apps on a handheld device.
It's great for businesses running custom apps tailored to their environment. It's also great for users hanging around home browsing the web, doing email, chatting with iMessage, handling financial transactions, taking/making phone calls tethered to the iPhone which may be in a charging dock somewhere else nearby, and performing other tasks using one of the million plus dedicated apps in the App Store, from a handheld device on a decent sized screen. It's my go-to device for 80+% of my computing needs, day to day. I turn to my iMac for more complicated work better served by a desktop class operating system on a larger screen.
There's nothing I do on my iPhone 6 that I can't do on my iPad Pro 9.7", except make direct phone calls, and since they're connected via iCloud, I can even make calls from the iPad Pro 9.7". The trade off is portability. The iPad gets used mostly around my home, the iPhone 6 on the go when I need to actually have access to the web, and my Apple Watch for customized notifications while my iPhone is packed away or in the other room. All these devices are linked together with my iCloud account, so which device I turn to is really which is most convenient for my situation at that moment.
So, is it worth it? For me, it is. However, only you can decide how much of Apple's ecosystem you can afford to buy in to, even if it seems cool otherwise. From a hardware viewpoint, unless you currently own and use an iPad Air 2, it's pretty much a no brainer.