I have used Redis for years, and have just started using Aerospike as a substitute for it by many reasons.
Although Redis and Aerospike both have great performance, Redis main problem is that it only stores data in-memory and does not have a clustering solution officially released. It limits the size of your database to the RAM size of your server, while Aerospike can be configured to use SSD to store information with no speed loss at all. Aerospike latency is incredibly low, even with high read/write throughput.
Aerospike best suits me because it is able to scale with performance and with no hard work, and different than Redis it is also designed to persist your data completely, minimizing data loss in any event. They have released a great video showing how easy it is to scale and manage a Aerospike Cluster, and also how it automatically configures itself even when there's a "disaster" situation.
