Been using this for a month or so and I like it a lot. Paid for it today. The Timeline feature is very well implemented. If they had a W7 version I would buy it too since I have to work on both platforms (generally I use RapidSVN at work where the PC is).
I used the free svnX for a long time but it's not a complete client, and the UI is a little non-obvious sometimes.
Occasionally I use the svn command-line tools, but I'd rather not make a habit of it, being a tool using primate!