The Installments will be replaced by the Activity Prizes. The Activity Prizes will eventually generate YEPs to Premium Members, much more than those generated through the Installments System; The higher the Premium Level; the higher is the Prizes.
Some Diamond Members generated an average of 350 YEPs daily in the first week; if they don't play for the rest of the month, they would have generated more than what they could get in installments.
You personally generated 1610 YEPs in Activity Prizes in the past 23 days, if we apply this average of 70 YEPs per day on the 180 days Membership, you will get 12600 YEPs compared to 12500 YEPs (5 Installments of 2500).
Of course this is in addition to all other benefits attached to the various Membership Levels.