Do You Really Need Full Frame?, tOP article.
...However, I wonder if perhaps we've now reached a real watershed for "good enough quality." The current 16-megapixel 4/3 sensor in the various current top-line Micro 4/3 cameras is so good that it seems like it might suffice for all but specialty and professional photography. And it's not too bad for those either.
I have been arguing this for a while now (basically since the Olympus E-M5 came out, along with the great lenses for it), and I'm tickled pink (for non-US readers, this means "delighted") that the author of one of the most popular and respected photo blogs now writes it too.
Don't miss this one either. I read it in Mike's book of collected articles, and I loved it, because to a degree, it freed me from the nagging feeling that one day I really "had to" use large format cameras if I wanted "the best" quality.