I recently spent a week around San Francisco and was very pleased with the 16-85. It remained on my D7100 about 80% of the time. From my understanding, you would see real benefit with a constant aperture if you're indoors a lot (let's say touring old castles and churches in Europe). Your primes could be used for that. Low light wasn't an issue for me as we were primarily outdoors. Perhaps you can base your decision at least partially on the type of travel you do? I hope that helps. Good luck!