COUNT SESSINE  It's OK - it's probably the best of all of the svn clients for the mac right now. The big thing about it is that you don't need a separate command line program - it's got subversion compiled in.

Otherwise, it gets confused a lot - I've noticed that it doesn't successfully 'clean' very often, and has a hard time with a lot of UTF8 valid characters. Also, if there's something really perverse about a filename, like that it has a forward slash in it, the command line client is OK with it but Zigersion barfs. That's ok - tortoisesvn doesn't do so well either.  
(Version 1.0.1)

COUNT SESSINE  Just to clarify, there are svn clients here, like ZigVersion, that are compiled with libsvn and can act as stand-alone clients. This isn't one of them - it's just a GUI front-end. You'll need to install svn either through fink or by building from source yourself.

That said, in terms of UI, this is probably the least-objectionable of the mac svn clients.   
(Version 0.9.9)