If you do much in the control panel, there's really no comparison - I've messed around recently with all of the forums you mention and threads has by far the best layout and thought-out control panel. With the updates to the public interface in threads 7 I prefer it over the others as well - cleaner, just better
My only current request for threads 7 is the ability to use the portal page outside the forum enclave - currently you have to forward people to the ubbthreads.php file when it would be nice to have it run on an index.php page in the root folder of a website
