I've developed games on Unreal and Unity (and bare metal etc). They have different pro/con (personally I prefer Unity). With Unreal you need hardcore coders and multi-platform targeting is hard. I think of it as the good, ol'-fashioned AAA big budget approach. Unity has quirkier graphics pipeline and some odd asset management things (works best with smaller teams), but it is incredibly easy to do basic behavioral scripting, there's a big on-line community driving their asset store, and cross platform delivery really works.
imo the real story behind the Unreal licensing change is that Unity has been crushing Unreal for marketshare in mobile game dev. Unreal had to do something radical or they were going to end up powering only some big AAA projects. "retreat upwards" is not a sustainable business strategy.
I certainly would like to see both companies healthy and pushing the platforms forward so I hopes this gives Unreal a boost.