---9 months later the same question.
I used to use the free version, before it became so restricted compared to the commercial one that I decided I was being bullied and quit. (I may be misremembering, but I think they may also have ditched support for .DBF tables, which was my main reason for using it.) But it IS very good, if you want to pay the money and if you're interested in searching the contents of your files. (If all you care about is filenames, I'd go with Everything, Locate32 or the new version of Listary.)
I used X1 for a while, too. Their viewer library (the Stellent one, I think) is still occasionally very useful, but its the only bit of the free version of X1 I kept. Can't remember anymore why I went off it...