I use MLdonkey on my Mac and it works great! It is much better than any other filesharing program I have used on the Mac. I doubt that is as reliable as eMule but it has some really cool features, like a remote web interface which lets you control your donkey using your web browser from another computer! Great for when you're at work or something.
There is a version for newbies called
mlMac that is really simple to use where as the pure client takes a bit of getting used to. You can also connect to the Fasttrack networks (Kazaa) and use Bittorrent through it (a bit unreliable at the moment) too.
Anyway there is no comparison for OS X p2p clients - so get on it!