Here's my take on the subject: Don't start with an overarching plot, but create one over the course of the campaign.
I mainly like the idea of an overarching plot for the flavor aspect, i.e. the sense of accomplishment it gives players as they work it out and achieve various things along the way, the way it ties the entire campaign together, the little "OMG! Now I see!" moments, etc. But I abhor some of the mechanical aspects it pushes one towards, esp. the certain degree of railroading it implies, the problems inherent in it if PCs decide to take off on a different tack or if the original PCs are replaced by new ones, etc.
So my particular solution, which I used in a 2 year campaign and am doing so right now in another one just into its 3rd year, is to start a campaign with no overarching plotline at all, but rather to let one emerge from the choices of the players/PCs. After the first session of the campaign, I threw out a dozen different plot options at the PCs and just let them follow the one they wanted. And from those choices arose other choices, and I also threw in a few more every dozen sessions or so. And while this is going on, I weave backwards and forwards to create the overarching plot. All you have to do is insert things into the game that can have various meanings, and only pick the specific meaning when you have to, and make that meaning the one most relevant to the PCs' backgrounds, choices and probable future.
So, for example, right from the start of the current campaign, I had someone powerful manipulating the PCs. When we started, I really had no idea who the individual or its agenda was, knowing only that it had access to significant wealth and magical resources, and that it was most likely tied into the background of the paladin and the wizard in the group. As time went on and the PCs made various choices, the BBEG in the background gradually got narrowed down into someone who was in Sharn (it's an Eberron game) and able to assume various disguises, someone who was at least decades and maybe centuries old, someone who had lairs in other nations, and eventually, someone who was really interested in items that could break binding magic. And so, the BBEG eventually emerged as a powerful rakshasa spellcaster. And the PCs eventually ended up with a climactic encounter with him which tied together the first 45 sessions of the campaign and the first 1.5 years of the campaign.
None of that was set in stone at the beginning of the campaign, and (as I just indicated) in many cases didn't even exist at all. but now if you go back over the details and the interconnections, they are absolutely ironclad. So I got an overarching plot without actually having started with one, and effectively got all the benefits of one without any of the negatives. All it takes is patience, flexibility and a careful eye for threads that one can weave together, with the understanding that one is weaving backwards as much as forward.
Hope that helps.