I'd rather have both.


But, i'd go for zoom first (at least for the middle to mildly telephoto range), and then maybe compliment that with a prime or two.


I would say that you can't argue with the image quality of a prime, and I guess you can't, however you can't argue with the versatility and speed (of 'changing' the lens) of a zoom. If you take pictures of things that won't hold a pose while you change lenses, or try to back up (assuming you have the space), you're just going to miss pictures, period.


If i'm carrying a prime in a candid situation, I prefer it in the 35-50mm range (on full frame), though unless it's a low light scenario, a zoom usually serves me better.


So, I guess I'm on the "depends on your situation" bandwagon.