In all honesty, I agree with River - GND makes very little to no difference in either direction.
1) On recruiting - very few companies care about GPA (grad or undergrad) anyway. Plus, these companies are going to find a number to grade you on regardless of GND (whether it is GMAT, undergrad GPA, etc.). Plus, the only GPA that these companies have to go on is your first quarter GPA - so obviously it is pretty meaningless to begin with. Thus, on the recruiting front, everything else (networking, resume, cover letter, etc.) matters A LOT more than GPA.
2) On competition at school - if you put a bunch of type A, business school students together at any school then they are going to care about doing well in their classes (GND or not). I would imagine that people strive equally to do well in classes at Kellogg, Chicago, Wharton, Stanford, Harvard, etc. regardless of the weight of the GND policies - and that's because each is a highly motivated group striving to do well and learn.
On the competition point further - Wharton is perceived to be one of the more competitive environments and Kellogg is perceived to be one of the least competitive b-school environments, yet Wharton has GND and Kellogg doesn't.
GND does not a culture make. Try to determine your fit with an overall culture, not with GND or not GND.