The thought is interesting, but the question is not as easy to decide as one might think in the first second. Most people always strive after what they don't have (which often can be a good thing) or which they can't possibly obtain (which may depress some people). However, if it was hypothetically possible that anyone of us was ever offered the possibility to change our lives permanently for a life in the Great Valley we ought to think very carefully about whether of not to accept that offer.
I daresay most of us are sort of "pampered" by the civilization we live in. Many of you have told about your problems with the society, but are you sure that those problems would not exist in the world of LBT as well? The Great Valley is not utopia. There are bullies, there is intolerance, there is some degree of racism, and Littlefoot and the others have often been faced with problems of a sort none of us ever had to deal with. How many of us have ever been exposed to hunger or thirst to the point where they might die of it? How many of you have ever been running from somebody who intended to kill and eat you?
As for the dangers we have seen LBT characters being exposed to, it is certainly nice to just watch them save and comfortably and always aware that none of the "good" LBT characters is going to be hurt. Being exposed to such dangers without such a reassuring certainty is definitely a totally different story. Many people dream about time travels and are thrilled at the idea of being given the "chance" to fight in a war of older times wearing shining armor and being perceived as heroes. These people often don't realize the reality of war and while the absence of war is certainly a point in favor of trading the Great Valley for our homes, the absence of situations which are much less pleasant to experience than being told about is not.
And is it not true that most of us would have a heart time not to touch a computer for a few weeks (let alone for the rest of your lives)? What about the people you would have to leave behind, what about your families?
I already mentioned the perils you would be exposed to in the land before time, but there are much more profane point you might want to consider before signing a permanent contract. Is there anyone here who is not a little uncomfortable at the idea of never enjoying the comfort of modern sanitary facilities (e.g. toilets) instead of some bush or whatever? And how thrilled are you of the idea of living on a diet of grass, and leaves, and perhaps some fruit for the rest of your live (or on insects and raw meat in case you are not interested in what the herbivores will think of you)? Perhaps the chance to take the form of a dinosaur would accommodate for some of these discomforts to some degree (assuming that you will be equipped with a stomach and a sense of taste better suited to deal with a dinosaur diet than our current stomachs and senses of taste are). But unless you have all memory to your previous live completely eradicated (and are you really ready to give up your personal identity like that?) I'm sure it will be quite a steep learning curve for anyone. What for example will you think when there is the first thunderstorm? Not many of us will have been in a real thunderstorm without some clothes and the chance to get at least into a tent within a few hours. There wouldn't be that comfort in the Great Valley. As I mentioned clothes before, in case you want to keep a human form in the Great Valley you ought to remember that your clothes won't last. The next clothing store is at least some 65 million years away (if we think of the land before time being our world before our time (as suggested in the introduction of the original movie)). And apart from that "problem" being the only human in the Great Valley might result in your being considered an oddity no matter what.
Here is yet another thing you should consider before you sign up for permanent residence in the Great Valley: Won't you become bored after a while?
Few of our members have ever even tried to think of what they would consider a an interesting land before time story within the limits set by the movies (that is without any crossing overs and elements not part of the land before time). How long would it take for all of us to get bored in a world with so much fewer possibilities than our modern world?
I fear that responses to this message may include the frequent reproach of me taking matters too serious. However, in this case I have to take it that serious to try to make it a discussion. This is also why my post is based on the assumption that we would have to trade our world for the Great Valley without any chance of return. If we could just walk in and out of the land before time just as we like it and without anything to care about I doubt many would not give it a try; so based on that assumption there would be little left to be discussed.