Hey, So having little music production knowledge and Ableton usage, I delved into this after reading many reviews. I also took a course on Push 3 (worth it) and am about 10% in the course. I also have a 49 NI keyboard which works well with Push. You can use the Push 3 as a audio interface and it works great - which I have (but it has some cons).
You will look at scales differently, with this machine. Easyu to play your triads, diads and extended chords. That blew my mind a bit. Beats, creation and playing around are so much more fun. Think less messing around with the computer and more focus on actual real phyical buttons. Also if you like to have buttons - this one has it. Although they can be a bit hard to press, the hardare is of a solid quality and it works flawlessly with Ableton out of the box. Also my NI which was a bit painful to install in terms of firmware and software, works well now with Push.
The price is concering, but with future updates secured and Pushs good customer track record, I feel comfy with this for years to come.