Most NC's are rolled with pre-aged tobacco, whereas Cuban cigars are typically rolled with very young tobacco. Most NC's are ready to smoke when you get them. Cuban cigars are usually smokeable in the first few months, then after that, you'll start noticing a change in taste. It will go through the fermentation process, ammonia will be released OUT of the cigar, and the tobacco blend will marry. After about a year or so, the cigar will taste good again. The longer you let it age, the more mellow it becomes.
Monte 2 is a great example... Got a fresh box in '06, smoked a couple and they were great. After about 2 months, I smoked another one but had to extinguish it as it tasted horrible. Waited a few more months, still tasted bad. Today, those cigars are now one of my favorites in the humidor - of course they now have over 2 years of age on them, ammonia scent is gone, and the tobacco has married quite well.
NC's - usually ready to smoke when you get them, and don't require much aging.
Cubans - general rule of thumb is smoke them within the first 3 months; after that you'll notice a change in taste, and they will require about 1 year of aging before they will be smokeable again.
Not all cigars are the same; though I hope this helps answer your question.
Oh, and always leave the cello ON! Just my opinion.