Just an update for any of those who were following my saga.
I've had the 17-55 F/2.8 IS(Thanks JoJo!) for a few weeks now. I haven't done any serious shooting with it, but I have tested the lens, shot for the sake of shooting, and have drawn some initial conclusions.
Likes:
1. It is an extremely useful range on a crop body. It lets me go from wide angle to med portrait in a single lens. Combined with a 70-200 on a second body and you're pretty much covered for everything.
2. It is a very sharp lens, F/2.8 is excellent and I wouldn't hesitate to use it, and stopped down it only gets even sharper. I've had other F/2.8 lenses that were too soft to use 2.8 with much confidence for critical work, this is not the case here.
3. I initially didn't think I would have much need for IS at this range. I was wrong, it certainly does have it's uses and will allow you to get shots that you otherwise normally wouldn't.
So what we have is a great range, very good sharpness at all focal ranges and apertures, and IS which is killer when the situation calls for it.
Dislikes:
1. The build/feel is certainly not on par with the L lenses I'm used to using. Now, I knew this going into it but it still bothers me and makes me questions how long term this lens can be in ones lineup (also see the reports of IS failures). The lens just feels sloppy and I dislike having the seed of doubt planted in my head about it eventually failing. On a good note, no dust issues yet!
2. The colors/contrast are not as good as my L's (17-40, 70-200) out of camera, which leads to extra PP'ing time to get the images to pop and look on par to the L's.
3. While the IQ is top shelf, the bokeh isn't the most attractive.
4. Flare performance doesn't make this a great choice from landscape photography, unless of course you like flare.
Initial conclusions:
So, all in all I think it's a very good lens and a great tool to carry in a two lens setup. I still simply like using my 17-40 better and I think the images are a bit better from it as well (though admittedly it's not as versatile as the 17-55 by a long shot). I have doubts that the 17-55 will last the test of time, it does NOT inspire confidence. It may last just fine, but I hate not having that confidence.
You may see me change out the 17-55 for a 24-70 down the road (maybe while still shooting crop, maybe if/when I make the move to FF). I still like my 17-40 that much more and having a 24-70 would give me more of a reason to bring the 17-40 along, at the cost of convenience for sure.
Bottom line is I think I made the best business choice for the cameras I am currently using, whether or not it was the best choice for my personal shooting is yet to be seen. It is certainly a very nice lens and an extremely useful tool.
Thanks for reading!