I use Canon and my wife uses Canon..... Yeah.
Nikon and Canon are about the same IMO. Stepping up in res but down in speed would be Hassleblads, stepping up in mobility and lens quality would be Leica, stepping up in convenience would be an iPhone or Galaxy Camera, stepping up in DOF would be a Lytro. Personally I'm not a fan of the 5D3 or the D800 even though the MP is high. I would prefer D4 or 1DX for the framerate alone. Either system would do. I would personally like to just switch to Leica for the lenses and portability but there is a special place in me for very portable, fully automatic, waterproof point and shoots just due to their versatility. Oh and yes, I do use a Sony TX20 for weddings as a waterproof shooter. I guess I want one of a bunch of sizes and formats just so I could pick and choose the right tool for the job.