A shitty merit, i have never seen anyone who can get a rnk rise from Full member to Senior Member, let alone Senior member to Hero or Legendary, if the forum dont want to let user get a rank up, why not cancel the rank immediately?
Actually, there are members that have ranked up on the rank levels you mention after the merit system was introduced. So far as Ive been able to work out:
4 Hero Members (from Sr. Member)
18 Sr. Members (from Full Member)
39 Full Members (from Member, 3 of them from lower ranks)
975 Members (from Jr Members or lower).
I dont want to repeat the links to the 22 top rank members here, but they are posted on the meta section this week.
True that the feat is way more difficult for the higher ranks, but feasible in principle.