I know this is old, I been using NGUI for awhile now, I like it way better than UGUI. You have less code to write and everything is clean , tweening s great as well in NGUI.
I do use UGUI a little , but I have used it a lot and can't see myself using it over NGUI. I'm a professional C# coder. So no idea how well it is in Play maker, I just picked up Play maker to try it , to help me speed up development for demos for my games. I hear its good for that since I already can program, I wasn't gong to buy it, but I been seeing other programmers giving great reviews.