iMesh is known as one of the most spyware-ridden pieces of software available. I strongly advise against using it because it can jeapordise the security and integrity of your computer. Having downloaded a spyware search-and-destroy programme, I found innumerable breaches of my privacy through spyware applications.
The one thing I liked about iMesh is that it provided the most reliable connection. Any Gnutella clients I have downloaded (LimeWire, BearShare etc.) have all had great difficulty finding an available server, whereas iMesh was available and up-and-running not less than 99% of the time.
So, if you are not concerned about your system security and your personal privacy, iMesh is definitely the best p2p client that I have found. If you are in any way worried about privacy, I recommend you delete iMesh and also install a spyware search-and-destroy programme such as SpyBot S&D (http://security.kolla.de).
Keep it real!