My two cents:
I'd choose the BenQ or the Dell for better contrast ratio
Both are scarily similar with some exceptions:
1. The BenQ has built in speakers while the Dell one does not (probably bad quality anyway but still)
2. The Dell has much smaller Bezels which is a definite plus (probably due to the lack of speakers and the BenQ having a built in power supply)
3. Both tilt reasonably well
4. The BenQ is $50 cheaper (before tax and comparing the two manufacturer sites)
Over a $50 difference I'd personally get the Dell for better image quality
But if you go with the BenQ, you could spend that $50 extra on something else like external amp, headphones, mouse, keyboard, etc.
