It's like only yesterday we got
BIGTOP-1867 in, delivering Gradle 2.4. Now I am looking into 2.6 and see a number of significant improvements (https://docs.gradle.org/current/release-notes) that warrant an upgrade. But perhaps it is worthy to wait a couple of weeks for 2.7, which already has an RC2.
Another point: our Docker images are still on Gradle 2.0 - we just have to bump them up to at least 2.4 and benefit from the performance improvements.