If you watch LLL drops; ones that don't get purchased as expired nor back ordered and actually drop, you will find quite a few LLL.us and LLL.biz everyday, but very rarely any other major gTLD. To me that speaks volumes as to value. If more inventory comes on the market everyday at reg fee, that really limits the upside value, unless it is a 3 letter word such as fix.us, cat.us, dog.us, and the like.