off the record - always go for the enterprise version if possible (i.e. you're not paying for it yourself). Noone will remember that you saved money if everything works fine but when there's problems, everyone will remeber it ;-)

On the other hand the enterprise versions are often based on older versions of the different community projects  than the latest community versions. If you need the latest technologies the community versions is the way to go.

as Nicklas Karlsson noting it is a better feeling if you have the JBoss support behind.

But at least it depends to what you want.

In the past (and different companies) I worked with the community edition and all works fine.

The installation was hosted within the company and the necessary uptime was not a 99,x% so it will be enough.

Nevertheless sometimes it was difficult to get answers to questions and bugfixes. We spend time to learn and fix bugs by ourself.

I'm not sure whether it was really cheaper than a EAP version with support ;-)

In the current enviroment we have to ensure a 99% uptime and to ensure this we decide to have the JBoss support with the EAP version.

Also I think the hot and newest feature is often not necessary in production.

If you think about the compatibility it is possible to use community and EAP with the same application depend on the customer's wish.