With so many people now owning these megapasses, I wouldn't be surprised if it's true that holidays may ironically be less crowded, because the people who own them wont want to "pay" to ski.
Alta was considerably less crowded on days the ikon base was blacked out last winter. Before that my experience working at kwood was the busiest days of the holiday weeks were the ones the tahoe value/local passes came off their blackouts.
It probably is worth dropping the extra money on the more expensive pass with no blackouts if you can swing it imo.