Just looking at the last 24 months of two typical pilot's career under CBA 2011.
One flies all his normal lines, no heroics/draft/etc, and retires. The other is regularly sick (since he's old ) and depletes his sick bank( bidding the same types of lines as pilot 1 and retires. At the end of 24 month, they both ended up with the same amount of money (absent some per diem and maybe over-8 international) in their pockets. Obviously, pilot 2 got that money along with a significant amount of time away from work. But, I think we would agree that he received dollar for dollar payout of his sick bank. There really was no downside for pilot 2.

Under CBA 2015, if the same thing happens, pilot 2 is no longer technically getting a 1 for 1 return on his sick time. He would have to account for the $110,000 dollars he gave up to use his sick leave. Maybe he doesn't care or have any choice but it's still money left on the table. It might still be worth it for some people depending on their situation - but, it's going to give some others a little pause.

Also, remember - when you do the math on the lesser of the three bonus options: Any sick time used does not count toward the over $520K earned in the last 24 months column.