I'm a little pensive. To begin with, I use two 6D cameras. I own 17-40/4L , 50/1.8 STM, 90/2.8, 70-200/4L and 150-600 VC. I almost never use 70-200, it only takes place in the bag, it's Canon's cheapest 70-200 without image stabilizer. Something that I have never owned is a 24-70 lens. Now that I have two cameras, maybe it will be different, but earlier I was satisfied with just 17-40 as an objective to walk with.
I received an offer to sell 70-200 for a good price and think highly of the two alternatives that have come up in the brain.
1. Sell my 70-200 and buy the new Canon 24-70/4L
2. Sell my 17-40 to purchase the new Canon 16-35mm f/4L
- 70-200 can be nice to have in certain situations. A few times a year for me.
- Will I find that the 24-70 is unnecessary when I have a 17-40? Or will it be the one and only lens? 
- I've been happy with 17-40 and wonder if 16-35 will be worth the extra money. 17-40 I only shoot with tripod in controlled situations and I've never felt to have IS.
I can believe that 24-70 with macro function can be a good solution if you are out walking with one lens only. The advantage is that 24-70 can take both landscape images + short telephoto images.
Where should I spend money?
Until July 31 it's campaign and I will get back 200 USD for 24-70 and 100 USD for 16-35.
Help me..... 

