We've got reviews of both over at sevenstring.org.
I haven't played the freelok yet, but another mod has, and has posted a review of each. As I recall, his final conclusion was that while the freelock has the advantages of being currently for sale (though, tromol-no's are now on preorder and should ship at the end of April) and slightly easier to set up right off the bat, the Tremol-no is the superior product in terms of feel (or, more specifically, lack thereof
) and overall performance.
