I like how easy it was to set up a cluster with two nodes in different locations. That way we could easily scale our apps if needed. It also has some additional features like caching for example. Nothing really. It did what we needed and that's all we need. We never had any problems regarding performance or anything. Just keep the number of nodes low until you have enough traffic to start scaling properly. Setting up a few clusters was relatively straightforward. Deploying code to them was not. But once that was done it was fine.