http://www.seatguru.com/airlines/Nor...ng_747-400.php
shows that 12JK on the 744 has a limited recline. 80JK is taken both ways.
http://www.seatguru.com/airlines/Nor...irbus_A332.php
shows that there is no 5JK on the 332, so I assume you mean HJ. Seatguru also says that that area can be noisy and people tend to gather there due to the extra space.
Are either of these claims accurate?