Thanks to Dave Williamson for passing along this great article on why sensor size matters. I'll never forget when I moved from a CoolPix-995 (3.1 megapixel tiny sensor) to a Canon 1Ds (full frame 11.4 megapixel). The images from the 1Ds were so magnificent, amazing and detailed I would spend hours looking at them in Photoshop.
With digital sensors size really does matter. As this article describes a large sensor gives you:
In the article Sean Arababi describes an interview with Annie Leibovitz:
NBC's Brian Williams interviewed Annie Leibovitz who, when asked what kind of camera one should buy, remarked the iPhone – "that is the snapshot camera of today... it's the wallet with the family pictures in it." Although I truly dig the iPhone 4S' new 8 megapixel camera and all the revolutionary technology crammed into the smartphone, the Sony-made image sensor is just not large enough to rival images captured with a DSLR – and that's expected. Apple describes its A5 chip, designed with an image signal processor, as "just as good as the ones found in DSLR cameras" and this might be true, but the image sensor is not – big difference between a signal processor and a sensor. It might allow you to shoot faster, or capture nice color and tonal range, or to use when you don't have a camera handy, but it can't match the quality of a larger image sensor that's comes with a higher-quality lens. Simply put, you can't squeeze a V8 engine into a moped. Then again, I can't make a call, text, tweet, Google Map a route, or play Fruit Ninja with my DSLR camera, either.
This expresses how I feel as well. I love my iPhone 4s. It is an amazing little package of technology but there is nothing that matches the lovely images that my 5DMKII turns out with a great piece of L series glass on it. I am still frequently stunned by some of the images a 5DMKII turns out with a Canon 24-70mm lens or a 70-200mm. You just can't beat a full frame sensor with a quality lens.