However you'll miss some of the performance improvements were done in 9.x series, and obviously in upcoming release we'll stop support for 8.4 version before 9.x one instead of yet.
However, you'll miss out on some of the performance improvements that were done in the 9.x series, and obviously in upcoming releases we'll stop supporting the 8.4 version before the 9.x ones (though that's not planned yet).