Joakim, connecting to a large ammount of ultrapeers cause a problem to everyone network, except for the person who searches from lots of ultrapeers.
1. When you do a query, that query is sent from each ultrapeer you're connected to. These queries will reach many times the ultrapeers you are not connected to, because each query search random ultrapeers. Therefore, the traffic between ultrapeers is upped a lot.

2. many ultrapeers gives poor results cause they can't route that amount traffic, thus lowering search responses by lowering the amount of peers you search.

3.the more places you take as a leaf, the more ultrapeers the network needs, meaning that 1)poor ultrapeers will be elected, 2)your search horizon is lowered

4. There are others factors, but I think I told you the biggest.

As a matter of fact, software locked number of ultrapeers rock! For me it is great, for you there will be less results, but everyone on the network will have better search results!