It does matter to which ultrapeer you are connected to, but there are a lot of other reasons for having low results. If you had a network neighborhood of many well behaved clients (the way it was when LimeWire had the only ultrapeers) you would have a lot better search results than you have now. That's why I think LimeWire should group their clients together.

If each servent vendor occupied a different area of gnutella, and if all the areas were well interconnected, it would be a lot more difficult for one vendor to poison the network for other clients. If all LimeWire / Bearshare / Gnucleus hosts were each grouped together, it would allow each vendor to implement new special features and experimenting without harming the network for others. Searches and downloads over the borders of the neighborhoods would be possible (although not every vendor's servent might be able to chat with another or show certain statistics) and if LimeWire turned out to return less search results then for example Morpheus, we would know, that it is LimeWire's fault.

The way it is now, when some servent seriously screws up, the gnutella network becomes bad for everyone.

just my 0.02€.