That "hint" to get > 30 concurrent connections is actually not such a smart move. The same text has been doing the rounds for a while now, but it doesn't mention that the limit was set to 4 as a means of rationing resources.
The connections on the server side are taken from a "pool", and if you have one client that grabs 30 of them, then the total number of concurrent users that the system can support will be seriously reduced.
In fact, 30 connections to a single client would be enough to lead many sysadmins to believe there was some kind of Denial-Of-Service Attack going on. They might or might not then take measures.
It could be a valid performance change to make if the browser was dedicated to a special intranet application and the appropriate server-side capacity calculations had been made, and if there was a guarantee that the browsers would not create connections to a public network.
