There are a number of articles about this, so it's hard to know specifically which one you're referring to.
That being said, it really depends on the tech stack. If you want a full J2EE implementation versus just a J2EE container, then the startup times will be very different.
For example, Tomcat can be started in seconds. On my machine in about 1-2 seconds. Of course this is a J2EE container. It doesn't include features such as EJB's. But these days, who really needs that.
Full J2EE implementations like JBoss and Weblogic for example will require much longer server startup times. Generally in the half a minute to some minutes.
Again, you really need to decide exactly what part of the J2EE stack you want, and if you're not going to fully use it, then Tomcat is great for quick startups.
As well, even if you use Tomcat for development, doesn't mean you need to use it for production. That isn't to say it isn't a good production server, it's just lighterweight.