If you haven't invested in lenses, then by all means try some out. Renting is a good idea.
I know people who take incredible photos with Nikon -- Zoomer comes to mind.
And I know people who take incredible photos with Canon -- Kady, for example.
The quality of your photos, in the end, lies with the photographer. The camera only helps. I've got Zoomer's D50 that she used to use and took some stunning shots with . . . and mine are CRAP :rofl1: