Being able to relatively clean slate a lot of the fundamental design issues of the Kee Engines systems, when translated to UE4.
The UE4's UI System is far superior to work with, and less error prone. This version naturally becomes much more error free as the interface between Lua, and the UI is intrinsically more graceful.
Quicker load times, DX10/11 has faster creation of GPU resources than DX9. This is one of the reasons the Kee Engine version didn't load that much quicker on an SSD.
Able to produce cool little things with relative ease, e.g. glowing headers/turbos, the photoscene. Future plans for the photoscene include placing multiple cars in the scene, perhaps having other props that can be added and moved in the scene.
Being 64bit and all the advantages that it provides.