What is most valuable?
This open source Application server is a good choice for Enterprises using J2EE . This gives much better value than Websphere and Weblogic. Easy to setup and self contained software. The product offers advanced J2EE features like queues and topics. Also provides for failover, high availability, support. Webserver can directly communicate with the database, Much cheaper implementation.
What needs improvement?
Level of customization is low as compared to other competitive products.Runtime diagnostics and DR (Disaster Recovery) features are limited as compared to Weblogic and Websphere. Since oracle now has Weblogic , they are introducing integration of other products like coherence into it.
What other advice do I have?
We chose JBossas it scales well, supports multiple nodes redundancy and has an integrated Tomcat which can be customized.The price is a big plus and out of the box implementation is good. Most people are skeptical to run Enterprise applications with ope source jboss.
Disclosure: I am a real user, and this review is based on my own experience and opinions.
A short comparison between Tomcat and JBoss showed me that Tomcat is an Engine Servlet while JBoss is an Application Server. The advantage in using JBoss Web Server and not Tomcat is if the user must deploy a web-app Enterprise (example EJB).