I'm using it under 6.1. When I upgrade UBB.threads, though, I use Beyond Compare, rather than re-installing hacks individually.
I think the only change needed is to use {$config['tbprefix']}Users instead of w3t_Users, in the changes to admin/showstats.php. And that really only matters if you're using, or may be using in the future, a custom table prefix other than "w3t_".
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