Human nurture vs Mutant nature?

So last week being an authentic X-Men BW comic book fan [BW: Before Wolverine] I made a point to go see X-Men First Class on the big screen before it leaves the two theaters in Manhattan still showing the fifth Mutant movie and second prequel [Wolverine being the first] of a seeming unending series.

To be honest my expectations were low - real low.  I foresaw stimulating visuals with a storyline that took me from one CGI event to the next.  Instead what I experienced was a tale about retribution and reciprocity wrapped in the familiar historical events of World War II and the Cuban Missile Crisis. 

For the first seventy minutes or so [with a noteworthy score setting the mood] it doesn't even feel like the X-Men movies before it.  Something I attribute to a script, casting and acting that only pays attention to the Mutant comic book world when necessary to remind you it's a franchise.  The rest of the time it's a true nature vs nurture story of two men that to their benefit and detriment cannot change who they are and who they wish each other to be.