When we choose tools….we need to chose best.
For development and low budget customers open source tools are good enough.
Better to have commercial support too for demanding customers.
EHCACHE: Better to use EHCACHE for Cache…if customer is demanding more support/performance we can ask them to upgrade to Terracota.
Tomcat: Tomcat out of the box is good enough with few tweaks. Those who need more support they can go with Spring Source vFbraic Server. http://www.vmware.com/in/products/vfabric-tcserver/overview