hello all, I've been shooting available light photography for the past year and a half, hence all I have in my collection are prime lenses. Just recently, I've been tasked to cover a few events but all the lens changing is quite frustrating and unprofessional, especially during crucial moments. thus I want to ask those more experienced shooters out there which would be a better choice for me, nikkor 17-55mm f2.8 or 24-70mm f2.8, in terms of coverage and long term usage. I use a d7000. I understand that the lens used is based on the type events but to those more experienced ones who have both, generally which focal length is more useful?