Upload & Sell: Off
As much as I would like the 2.8, it is not as important to me. I do shoot events on occasion, but I shoot with a friend who has faster lenses, and with the improved ISO performance, I think I can probably live with f/4 when needed, even if corner performance is not great at that aperture.
For most of what I will be shooting, I will be stopped down to f/8 or f/11. And this lens certainly will not be my walkaround lens. I was planning on getting the kit with the 24-105 for that.
Being able to use filters is also very important to me. I have a set of Lee filters right now that I absolutely love using and would not want to build a new camera kit without the ability to use those on my wide angle lens.
As I see it, with importance to me, the pros of the 16-35 are:
-faster, f/2.8 which is of mild interest to me but not a deciding factor
-wider, 1 extra mm, although since I am used to crop frame its more like half (or .6 extra mm). While noticeable, may not be nearly enough of a deciding factor
-sharper. Maybe a bit sharper wide open, but stopped down probably the same as the 17-40.
-Cost... its double the price of the 17-40 and that price difference is a big deal to me, makes the upgrade easier to swallow and allows me to have some extra money for accessories, etc.
-82mm diameter. This is kind of a pain as it would require new filters and new adapters. Extra cost on top of the already very high cost.
So for most of my purposes, it seems like the 17-40 will be able to equal or possibly surpass my 10-22, if for no other reason than its on a full frame system and the benefits the full frame system will provide. Of course I will miss that 1mm at the wide end, but for me, is that 1mm reason enough to spend twice as much on a lens?
There are still of course the other benefits. I was able to use the camera at my local shop yesterday for about 10 minutes. The camera felt great to hold, and as solid as my 60D felt, the 6D just felt more solid and a bit better. The viewfinder was bigger and nicer. I took some pictures with it to compare to my 60D on my 70-200 at 200 and even though the subject filled more of the screen on the 60D, the quality was definitely better on the 6D, although that was from looking at 100% crops, but even my girlfriend said she could see the difference.
alex, not trying to dispute what you are saying, just trying to see if it really applies directly to me and whether its important enough to base this decision off of, as it stands, I am still not 100% convinced about upgrading to full frame, its a lot of money and so far I am basing it off what I see, but again, having never used full frame or the equipment I am considering, its hard to know whether its really worth it.
boingyman - sorry didnt see your post while I was posting. Yes the decision between the two is tough, and I am nearly convinced I am ready to upgrade to full frame, but I do have reservations.
About keeping the 60D, probably not. I would like to, but I am not sure my budget allows for it. Although with the price difference between the 17-40 and the 16-35, it might become more of an option...