Correction...Extra Spins = more dead spins - every time.
Extra Spins does not mean extra wins.
Many a slot has the trigger of doom - Rapist with 4/5 scatters, Bonanza (anything over 4), Evolution (evil ablutions) 4-scatters and not get the flying squirrels evolved. DHV is another one, the 4-scatter 20x payment tends to equal about what the feature will pay. IGT's Cleopatra is the only slot I ever noticed a better feature return on for 4-scatter triggers, even if the amount of spins was the same, I found it more likely to retrigger.
Extra spins = more dead spins - most of the time.
2006x
Not one single dead spin and the multiplier reached 22x from 17 spins