Nicotine+

Much, much better overall interface than the original SoulseekQt client.
All settings are neatly organized in the same modal window.
Has a dark theme, and lets you customize icons, fonts and colors.
Lots of features too.
Queue handling is much smarter. It can automatically open and close upload slots depending on bandwidth usage, which prevents users with low bandwidth from clogging your queue.
It has an extensions system and a couple useful plugins, can run arbitrary commands on certain events, show virtual folder names…
And it's open source.

I had minor performance issues with the upload screen when there are hundreds of lines, but aside from that, everything works perfectly.

I don't understand why not everybody ditches the original SoulSeek client and replaces it with nicotine+. This client is a piece of art, works on any OS that supports python and is fully open source, actively maintained and really like it should be.

The only feature that might be missing is you don't see locked shares where you have to ask for permissions to download files from someone. I don't miss that at all.

Love the Nicotine on Linux, it's rock solid. On Windows, not so much - the original SoulseekQt seems to be snappier and some functions like the search are still better implemented there.