In my opinion, neither Clark Kent nor Superman is a disguise. Sure, he has friends and family that he tries to protect, but trying to disguise himself as one or the other is just drawing attention to himself. Lets start with Clark first. He may have been born on Krypton or, as in the John Byrne revamp, of this part which I may be the only fan of, on Earth due to a birthing matrix, but no matter what, seriously, how many of us can remember what happened a few days after we were born? So Kal-EL is out of the question as being the real personality. Its just a name that Superman, not Clark, uses. That leaves us with Clark and Superman. Even if he was born on Krypton, he was raised on Earth, as a human, Clark Kent. The whole argument about him being special or whatever because of his powers is totally bogus. Why? Would it really make sense if a baby, a few months old or not, could really be born with incredible powers and, not knowing how to control them, somehow doesnt cause millions of dollars of property damage? That means that the best and most realistic way of having him discover his powers is to have them develop slowly, like star emerging during his teenage years and finish by his late teens. So while the teenage Clark Kent would be smarter, faster and stronger than most of the other kids his age, he wouldnt be superhuman and therefore, wouldnt be treated differently by his friends, like Pete or Lana, or his parents. By the time he has all of his powers, hell have practiced how to hide and control them. Now for the personality: His parents would have taught him to help others at all times, and that he has a duty to his country and the world, in other words, to be a complete boy scout, no matter what, if he was their biological son or not, or whether he had powers or not. Well get back to the boy scout thing in a while. Anyways, yes, Clark Kent is who he is.
Now, on to Superman. Clark is who he is, Superman is what he can do. Even the Silver Age version admits that. The combination of his powers and how he chooses to use them thats what makes him Superman. Superman isnt Hancock, he isnt going to beat up a mugger, then literally throw him into jail and go and grab a drink. Superman would step in the way, and let his expression speak for itself. Mugger breaks his club/stick/whatever, and, panicked starts to run off. Superman flies overhead, grabs him by the collar, brings him to the police station, and returns to the victim, checking on them to see if theyre okay, and if they have everything with them, all in a calm, confident, yet gentle and caring manner. That, not fancy colors or the incredibly awesome ability to fly, is what makes him Superman. Now, Im getting to the Clark-or-Superman thing. Honestly, I dont see the need for a disguise. I mean, hes Superman. Why would the average person wonder if he has a normal life? Hes Kal-El from Krypton, thats all. Theres no reason to suspect him of being Clark Kent. I mean, is anyone really going to notice that Clark and Superman have the same personality? I mean, the boy scout thing I mentioned earlier actually helps this way. With Clark, being a complete boy scout will get him considered a dork and ignored. With Superman, however, its a belief, an ideal. Parents are going to use him as a role model for their kids, the same way they used guys like Christopher Reeve in the real world. Another thing is that Clark Kent already has a whole life built. Why would he tear it down so he can be Superman for real, and have Clark as a disguise? Thats Batmans job. Bruce Wayne is his name and a disguise. Batman is who he is. But, unlike Batman, Superman has friends, like Pete, and Lana, who I mentioned earlier. By making Clark a disguise, hes severing his ties to the real world. A huge point that I mentioned at the beginning is that trying to disguise himself is just calling attention to himself. I mean, look at how well that worked with the Reeve or the Silver Age versions. My opinion is that he shouldnt really disguise himself. I mean, Clark and Superman have the same ideals, but so do a lot of people in Metropolis. I mean, Clark uses the power off the press to combat evil and corruption, and to fight for truth and justice, the kind of time when Superman cant be the hero. The only major things he would be doing is to but on a pair of glasses and hide his powers as Clark, while as Superman, he should remember to forget personal details, like who adopted him and where he grew up. Now, Im not saying he should pull an Iron Man and go Im Clark Kent. Im also Superman. But the disguise is really unnecessary. Now, if its someone like Lois Lane who has constant contact with Clark and Superman, it goes something like this: Metallo attacks Metropolis. Lois and Clark hurry to the scene Lois is about to turn to see if Clark is right behind her, and to discover that hes not there, but just then, Superman comes flying out, punching Metallo until hes a pile of scrap. Lois stands there, transfixed, until he leaves, and then turns to see Clark standing right next to her, taking notes. How does this work? When hes out of site of Lois, whos hurrying to get to the scene, Clark sneaks off, changes to Superman, and comes flying out. In the few seconds between when Lois sees Superman flying off and when she turns to see Clark, using superspeed, he changes back to Clark and is right next to her. Boom, no reason to suspect him and no lame excuse like I bumped into an old lady on the way. This is why Clark Kent and Superman are the same, not two different parts of his personality. Well, thats just my opinion. Tell me what you think.