I got used to the syntax pretty fast, to the point that I actually kind of like it. My complaint about streams is how slow they can be. If you're doing collection transformations often, the time spent turning your objects into streams can kill your performance. I'm worried it's going to reinforce the old myth that functional programming is implicitly slow.

It will be a lot better with value types in Java 10 (hopefully).

That's one reason (of many) that we use Eclipse collections, formerly known as GS Collections. :) It also closes the gap on weaknesses in JCL like immutability vs mutability, and a nice improvement to the interfaces.

I know even use it in personal projects in place of JCL wherever I can.