Clone Troopers and Stormtroopers are not the same. It is true that the first generation of Stormtroopers were clones of Jango Fett, and many Clones still served the Empire well into the Original Trilogy, after the Clone Wars, the Empire decided to recruit natural born humans instead of using clones. Emperor Palpatine (Darth Sidious) thought that having an entire army that would be forever be made up of clones of a single person would make them to susceptible to corruption, considering how many clones resisted their mental conditioning, explored in season 6 of Clone Wars, and refused to kill their Jedi Generals, because they developed a personal connection with certain Jedi or though it was a Separatist trick. In was even an incident in the old Expanded Universe the cloners on Kamino tried to start a rebellion by using Fett clones, though it failed, it showed the risks of using only clones from a single source and ended the process for good (Star Wars Battlefront 2).
As a result of this it was decided to recruit naturally born humans from not only the systems of the Core Worlds where most humans would be loyal to the Empire but the impoverished worlds of the Outer Rim, like Tatooine, ensuring loyalty by promising a better life, an example of this being Luke's friend Biggs Dark Lighter. Luke himself even thought of joining the Imperial Academy. Not because he liked the Empire, but because it was the only way to get away from the planet and if his aunt and uncle weren't killed probably would, with his skills he probably becoming a TIE Fighter pilot, or worse, Sith. Imagine if Vader or Sidious got ahold of him with out any prior Jedi training.
However, this would also have its own drawbacks. By recruiting from naturally born humans that would have no mental conditioning there would be the risk of them defecting to the Rebellion, as in the case of Biggs, who did so because of the atrocities he witnessed being committed by the Empire. Another being Han Solo, who obviously didn't join the Rebellion right away, but was as Imperial Officer and went AWOL after witnessing the abuse of the Wookiees and rescuing Chewie. This might also be the case for John Boyega's character Finn, who is dressed in First Order Stormtrooper armor, in the trailer, and may be rethinking his decision to be a trooper. Anyway, as a result of this the Empire could lose valuable soldiers and intel to the Rebel Alliance.
Another draw back to recruiting naturally born humans was that they were subpar soldiers compared to the clones, and were more likely to hit their heads on an opening door (Episode IV) than hitting a target, and getting the crap beat out of them by a bunch of teddybears. Commander Cody, a surviving Fett clone, in a databank entry from ,"Star Wars: The Force Unleashed II", laments at the ineffective ness of natural born recruits and notes that he would sacrifice an entire platoon of recruits for the chance to have just one Fett clone. Darth Vader himself even hated using naturally born troopers and preferred to use the 501st Stormtrooper Legion as his personal battalion since it was the last unit that was purely made up of Fett clones. Most of the Stormtroopers who were on the Death Star in Episode IV, attacked the Rebel base on Hoth (V), and fought at Endor (VI) were from the 501st. Also recruiting rather than cloning left the Empire open to infiltration. Before when Clone Troopers were in service it would be difficult for a person or most spies to infiltrate the troops because they would have to fit in armor that is meant to fit an entire army of clones who have the same exact body. During the war some spies did pose as Clone Troopers, a Commando Droid in season 1 of Clone Wars, as well as, Bounty Hunter Cade Bane in season 2, though the subterfuge didn't last long. However, during the Civil War (Episodes IV-VI) it would be much easier because not all Stormtroopers have the same body type, thats why none of the Stormtroopers in Episode IV realized that Luke was, "...too short to be as Stormtrooper!"(Leia).
At first glance this might seem a bit of a contradiction because Leia's remark would indicate that all Stormtroopers are the same height, but this is not the case. This is because the Empire's recruiting process was probably similar to America's at the start of World War II. This being for a man to server in the war, at that time, they must be ranked A1, which meant that basically all recruits had to be about; 6 feet, 150-200lbs, have 20/20 vision, and be in peak physical condition to be put in to service, or else be ineligible to fight. This process can be shown in the 2011 film, "Captain America: The First Avenger", where Steve Rogers is initially not allowed in to the Army because he is; too short, thin, and sickly; or in the case of the original comics suffered from Polio. However, as the war dragged on and the Army had to make up for the losses suffered throughout the ongoing war, it had to get as many recruits as possible and thus abandoned the older selection process. This could be similar to what could have happened to the Empire's recruiting process, as it would need more and more soldiers to hold back the growing Rebellion and keep the Empire in power as long as possible, the Civil War, in the Old Expanded Universe continuing long after the destruction of the second Death Star, over 20 years
From this there is no doubt that Clone Troopers and Stormtroopers are completely different, from the circumstances of their existence to their effectiveness and ineffectiveness of their abilities in combat. And with the coming of, "Star Wars Episode VII:The Force Awakens", maybe we'll see an evolution of the Stormtrooper Corps. Maybe we'll see troopers that will actually be the badasses that they should have always been. --Seal Team 6-- Star Wars Style Baby!:)