Tbh I dont know if U4 is good, but it's propably better than Unity, simply because Unity is shit.
I think in the end the question is, do you care more for yourself / artists' / programmer's unwillingness to learn and work on your inadequacies, or do you care for the quality of end product? Unity is so lazy that even the homeless guy who is begging for a new computer could make a grass level in 3d, and now thinks he's a game developer. Unity is the ultimate hello world maker for people who can't program. Other than that, everything else than Unity probably gives a much better end product, simply because Unity is shit by default. Unfortunately people dont realize their code is just hello world, continue working on it way past its usefullness and release it as early access game. You can see the end results by the thousands on Steam.