The short answer is it depends: there are two slightly different products on the B777-300ER.
The majority of the B777-300ER and all of the new B777-200LR aircraft have Qatar’s new fully-flat business class seating on board, which will eventually be retro-fitted across its long-haul fleet.
http://www.businesstraveller.com/arc...business-class
A few of the B777-300ER were delivered before the seat had been approved, and so these have a slightly older version of the seat - still very comfortable, but not fully-flat