We are seriously evaluating both Cassandra and HBase in our organization. We are very pleased with the performance and ease of use of Cassandra and will start the same exercise with HBase soon. However some people in the organization feel that HBase has a larger comunity adoption. I understand that Cassandra has been deployed within Facebook and is also at Digg and Rackspace. I also went through the survey that Jonathan had conducted a few weeks back.

I am interested in hearing from those of you if there are any who have ditched HBase for Cassandra. If so why? Also, perhaps this is not a question for this list, is HBase used for real timish applications and if so any ideas what the largest deployment is. It would help me in swaying the folks towards Cassandra. Any help would be appreciated.