[NSNumber floatValue] is expensive, this patch removes the need for floatValue during animations by using an array of floats in an NSData container instead.
Optimization - eliminated costly [NSNumber floatValue] calls
Since animation should not change in size (frame count), the need for an auto growing NSMutableArray object is really not there. Do you see cases in which one would need that flexibility? If not, this is an easy and effective optimization.