The sensor size debate is one that will probably never end. It’s just too polarising of an argument. On the one side, you’ve got the “Full frame = king!” lot, and on the other, you’ve got “Nope, doesn’t make a bit of difference”. Two extremes. The truth, however, is somewhere in the middle, if you look at things objectively.
There are definitely benefits and drawbacks to differently sized sensors, but there are also many situations where it really doesn’t matter. In this video, Marc Newton at The School of Photography takes an objective look at cameras with three different sizes of sensor – 35mm full-frame, Canon’s 1.6x crop APS-C and Micro Four thirds to see which might best suit your needs.