Not them in particular but I'm currently testing Chartbeat and Reinvigorate (both Woopra competitors it seems) on my blog until I decide which one I like more. To be frank I don't like either. One is only about what is happening now (chartbeat) and doesn't tell you things like how many visitors you got in the last month. Reinvigorate tells you those things but all the data is spread out over tons of pages and you have to click around several times to get what you're looking for. I used to use Mint for all this (but not as realtime... you need to update it to see new numbers) but it needed its own database and I wanted to go with a much more simple setup on my jekyll site. No sql anymore!

chartbeat screenshot: http://dl.dropbox.com/u/186198/Screenshots/o0-4.png

reinvigorate screenshot: http://dl.dropbox.com/u/186198/Screenshots/mrva.png

Yep, I have used it on a couple of sites now.

It is great to be able to see your traffic in real-time if, say, you have just been techcrunched. But day-to-day, I found the Java desktop interface pretty hard to fathom.

It looks like they have a new web interface now though, which could be much better

We used it on our site Prophecy.co.za for a few months. It's very interesting to watch, and can provide some interesting insight, but for us at the end of the day we decided it's not worth it. However, when we have a fancy office one day I'll put it up on a big LCD in the reception area :)