I have incorporated their search wijit into my blog yesterday. It was easy to install and customize (you may see it now in the right-hand sidebar under my brief bio), and I’ve actually had a lot of fun playing with it even at the installation level. I put it up late at night, and in the morning I’ve already enjoyed the stats they provide. I am impressed, and extremely pleased.
If you aren’t yet playing with it, do give it a try. Many bloggers, Seth Godin included, are using it now. If you’re running a blog, replacing your default ‘search’ function with this thing is, in my opinion, well worth it.