To take the verse to mean, "If anyone disagrees, its not important", is to miss all of what Paul previously wrote, and to ignore the fact that things spelled out clearly in the Bible, like this, are not generally left up to people's personal feelings about it.
Its important to take this entire passage about headcoverings in it's context, which can be found at the beginning of Chapter 7: "Now, concerning the things whereof ye wrote unto me..." Apparently, the church in Corinth had written a letter to Paul, asking him about various subjects. Consider how, over the next few chapters, how Paul bounces from subject to subject, many totally unrelated. Even in Chapter 11, he speaks goes quickly from the subject of headcoverings/hair then immediately to the observance of the Lord's Supper, without skipping a beat. This goes back to 7:1-the letter. From this, as we go through the various subjects, we can ascertain what the questions were-in this case, (and history backs it up), women of the Roman culture, thus, all the areas where Rome held sway, which would include Corinth, had stopped wearing headcoverings, and were instead inventing new and complicated styles of wearing their hair, which had been previously covered up. The women were competing with each other in hairstyles. So, I suppose, from hisory and the answer Paul gives here, the question would have been akin to "As women are ceasing wearing headcoverings, are our women allowed to stop wearing them as well, or must a woman stay covered?", or something to that effect. Again, by his answer, we see it was something like that-Paul goes on to talk about the importance of a woman being covered-it represents her head, man, and the man is to be covered, which the man, whose head is Christ, is to remain uncovered, lest he cover the glory of God, being made in His image. There is no doubt left that a woman SHOULD be covered, and a man should NOT be covered, and to do otherwise is to make both parties unfit to pray or prophecy, and that would inlcude ANY prayer, not just within the context of the assembly.
Then, Paul continues by likening the hair to the covering-a man's hair should be short, hence, he is then uncovered if his hair is short. A woman's hair should be long, hence she is covered by her long hair, which God gave her FOR a covering. Hence, a woman should not have short hair, and a man should not have long hair.
Paul's wrap-up comment, then does not say we don't have to be covered, its not important, because he just spent a lot of time and space to emphasise that it IS important. Rather, it goes back to the original question: the WEARING of a piece of cloth as a cover, and THAT, the church has no custom of. In fact, that is so true that we don't even ever see it as an issue spoken of in the Old testament.-it was always purely cultural in the entire region, not a sign of Judaism. The hair was ALWAYS the covering, even from Eden.
By the way, blad is not uncovered-bald is an extreme-even the Jews were told not to shave their heads, because that was how many of the heathen nations wore their hair-uncovered is merely 'short', covered is 'long'. We could get into an argument about what constitutes long and short, but seriously, that's picking at nits, it's a way to disregard what the Bible clearly says. Its easy really: if the hair is too short to wear as a 'veil' or a 'cover', then it's short. If it's long enough to wear as such, then its long. Paul gives the answer by how he likens them. So, if there's a question that it MIGHT be too long for a man, the cut it. If there's a question that it MIGHT be too short, for a woman, then grow it out. Its not hard, not brain surgery. Common sense really does fix the problem.
As for how certain people of different faiths wear it, that means nothing but a hill of beans-its what the Bible SAYS that matters. If Fundamentalist women disobey the Bible by wearing short hair, that doesn't make the word of God of no effect. If Charismatic women wear their hair long enough, that doesn't make it of no effect, either.