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Big Puku
Rollover points usually go to waste since they expire and do not accumulate. I.e. they only have value if in the next year you don't fly enough to requalify and are short by less than the rollover amount.
Whereas a banked year saves a whole year of status (albeit may not be redeemed for many years), at a discounted rate.
It depends on your future travel as to which is better.