You can expect the connection limit to be enforced much more strictly in future versions, since people with lot's of Ultrapeer connections can reduce the overall Gnutella performance, while only marginally improving their own search results. - I doubt you will have more than 25% more search results with 20 connections, than with let's say 6.

You can imagine it like that. There are 16 ultrapeers, A1 to A4, B1 to B4, ... , D1 to D4. A1 to A4 and B1 to B4 [...] are connected to each other directly, so being connected to e.g. A1 and A4 at the same time will not increase your search horizon. With three connections the mathematical probability to have _one_ useless connection is ~60%, with six connections the probability will be 80% that you have _three_ useless connections.

That's why increasing your connections does only hurt the network.