The performance benefit is
huge.
I understand not wanting to learn another build tool, but I have no regrets where I've moved to gradle. It's so much faster on a project of any size it's stunning.
90% of maven projects don't do anything terribly complicated. Porting them to gradle leaves them uncomplicated and unexciting. I just wish there was a standard release mechanism. Poor as mavene-release is, at least everybody uses it and understands it.