I have used or tried most clients out on the net for p2p networks.
I first tried kazza, it worked fine until it got shut down. Some minor bugs in it. but hey it worked. Then I went to shareza same thing new gui interface and multi-network capable. Worked fine with verison 1. But that all changed when they updated the software. It went to hell in a hand basket, never could download anything without it be fake or corupted in some way. Then it was bearshare nice program hated the interface and all the silly pop-ups wanting me to upgrade etc. Now I'm useing limewire 4.9.23. the latest on the net. DL's run faster than anything I ever got on shareza or kazza. etc. The other night I was dl'ing a file and it was almost 200KBPS transfer rate!!
Now show me a client that will give that to you for free! And even tells you when an update is out and lets you select what type of update you want.
In short Limewire is the one I will use until something comes along thats better..