I've been away for a while and lost my AP access but I'm back and just back from a great holiday in Cambodia and Vietnam. I took my D700, 28-300, 16-35, 50mm 1.4g all in a Case Logic 203 bag. It was a dilemma for me wondering what to take as size and weight neede to be kept to a minimum . I purchased the bag and 28-300 for the holiday and was glad I did because it stayed on the camera 90% of the time and the bag was a perfect size to hold it all.
There were many times where I wanted to swap but as I predicted, it was too much of a pain in the butt in the circumstances not to mention the risk dust entry because of undesirable " changing" environment. I only used the 50mm a couple of times and the 16-35 on occasions when I knew there was going to be more landscape than people shots.
I guess the trade-off in quality and was well worth it as I found myself continuously zooming in and out to frame different shots within in few metres of each other and I would have gone crazy swapping or worse, miss the moment altogether. By the way I had my family with me, so consideration to them was a major factor also. I've attached a link to photos for those of you who would like to veiw and comment/critique some of my "family photos" using mainly a Nikkon 28-300 f3.5-5.6 VR. The shots of Trang An and Halong Bay (the last few) are mostly with the 16-35 f4.