I’d continue working with UE4 and try releasing our game 
I’d probably check it out, play around a little bit, then come back. I can’t imagine it being significantly better than UE, all aspects considered 
I can tell you from first-hand experience that making the decision to switch engines for an ongoing project is a decision not to be taken lightly. Changing requires a lot of rework and a lot of learning. We switched to UE4 from Unity, and it was the right choice for us, but it’s one we agonized over for a long time. In my mind, UE4 is an order of magnitude better than Unity for what we’re trying to do, and it was still a hard choice.
If they were to release the FrostBite engine, I would definitely check it out, look at how they do things, etc. But as long as Epic keeps doing great work and the community keeps being helpful and supportive, I think I’d be very unlikely to contemplate a change, even if an engine came available that was undisputedly better. Having played with the various demo projects at the Epic booth this week, though, I’m skeptical that anyone’s going to come out with an engine that’d definitively “better” than Unreal.
In reality, the AAA engines (UE4, CryEngine, Source2, Frostbite, etc.) are all pretty , and they all have strengths. In every single case, there’s something you could point to that the engine does better than some other engine. We’re really spoiled to have so much choice these days, especially those of us who don’t work for AAA companies able to afford the engine fees of the old world order.
So, while I would rejoice if Frostbite were released free, because I think it’d be a great thing for the industry, my feet are firmly planted in Epic soil for the foreseeable future.
I would like to try out and play with all the AAA engines but I would probably have to stay with UE4 as I’m not a programmer so BP’s are a god send to me, I can make all the assets for a game I want but they would be less then useless without any programming:p
I mean I would probably stick with UE4 anyway because I like the engine this community and the devs:)
i would still be here, met a lot of new friends here, wonderful community
its not the engine that draws me here, its the interactions i have had with this community and epic games that makes me love UE4