That is false.

The difference between a leaf and an ultrapeer is that one of them routes traffic between leaves, and the other doesn't.

Plain and simple. They are both just as hooked into the network as anyone else.

Most people, in fact, prefer to be leaves, because, until a couple of months ago, the bandwith necessary to sustain many connections as an ultrapeer was prohibitive. But now it is not so.

If you're not an ultrapeer, don't worry about it, you still have access to as many files as an ultrapeer.