Few thoughts:
Lenses are really best compared lens by lens. Canon, for example, offers the MPE 65mm macro which is a unique macro lens on the market - Nikon doesn't make one (but its not the only way to get high magnification shots of course - nor is it impossible to beat it). However Nikon offers some of the best wide angle lenses including one or two outstanding wide angle zooms (there's a few canon shooters using adaptors or a nikon camera just for that).
Things like the sensor tech are also short term - 5 years or so ago Canon was totally ruling the roost sensor wise - now its Sony (Nikon uses sony sensors and Sony have sunk something like 5 times the R&D money into sensors than the others just because they wanted in on the market so had to come to the table with something outstanding to get a foot in) in a few years it could be Pentax!
Most differences are not going to appear in standard shooting in good light. It's when the light is poor - when the situation isn't normal - when the little differences come out. Certainly any DSLR on todays market and any brand is capable of outstanding photography.