All of my previous work was implemented inside Unreal 3. Unreal 4 is going to cut development time down, by a huge margin, despite having to learn its new features. In the next few days, I am going to use whatever free time I can scrounge up to import the CB750 asset into UE4, to illustrate the difference in visual quality.
UE4 is also going to allow me to develop all of the programming with its new node based visual scripting system, blueprints. This means less time wasted on programming, more iterations, easier bug fixing - which results in a much more playable experience, more time for experimenting and polish.