For uncropped images, a bigger sensor is magnified less than a crop sensor, which usually has a positive impact.
Image quality differences are most notable on small prit's viewed up close. It's not about making big prints. With as little as 8 mp you can make entire wall-sized murals. This link busts some misconceptions about print resulution and print size.
http://www.photokaboom.com/photography/learn/printing/resolution/1_which_resolution_print_size_viewing_distance.htmUntil recently, only the full frame lenses were "fast" ie., larger maximum apertures.
Because of shrines losses due to diffraction, the full frame sensor has the least negative impact when using smaller apertures. One can use a full frame camera at F11 and still be able to record extremely fine detail, while the APS-C camera will start to lose fine detail at F8 and the M4/3 at F5.6.
For studio, landscape and architectural/real estate photography, you can get a variety of lenses that offer tilt and shift. While you can use them on APS-C cameras, the focal lengths that these are available in are really optimized for full frame.
Build quality is usually better on full frame cameras and lenses, but as the industry consolidates on smaller cameras and the public demands better quality, there are more options.
These are very broad generalizations. I use both full frame and a very good bridge camera with a 1" sensor.
Don't believe the myths that you need more mega pixels to make larger prints, or that you can't make a giant print from a tiny sensor. Just take a look around, and you'll see Apple bilboards that show images taken with their iPhones, and they look great.
For uncropped images, a bigger sensor is magnified... (