I have been using Oracle GoldenGate since 2011, right 2 years after Oracle acquired the company. It was an awesome project back then with version 10, but Oracle has continued adding tonnes of features to it ever since and this is just the best replication solution i have worked with.
I have done all kinds of replication using Oracle GoldenGate. Be it homogeneous, heterogeneous, unidirectional, bidirectional, on premise , on cloud (Oracle Public Cloud), integrating with JMS (Java Messaging System), we have done it all. We have loved the product so much that we have over years replaced all our existing replication infrastructure using Oracle GoldenGate.
I love that you can perform changes in almost zero downtime, replicate millions of data in sub seconds and their is large online documentations and forums to help you with troubleshooting any problems.
This doesn't requires a lot of expertise to begin with and overtime, you will love working on it.
Oracle GoldenGate now also comes with many GUI based tools like OGG Studio, OGG Director, OGG Monitor and OGG Veridata. These come with additional cost, but are great add-ons. Review collected by and hosted on G2.com.