I have a need for a wide angle lens for my 7d. Preferably something fast, 2.8 or better.
I had a 24-70mm f/2.8L I, as well as a 17-35mm f/2.8L (yes, 17-not 16). I sold both because I didn't use them, and picked up a 50mm f/1.2L to upgrade my f/1.4 for portraits.
I would like to use this lens for indoor candid uses primarily, hence f/2.8 or faster. I have a budget of ~$600, but I am in no rush to spend that much. I don't do a lot of landscape, but occasionally I will dabble in it, as well as the sporadic attempts at astrophotography (too much light pollution where I am). I like to shoot wildlife (on a budget), so I have no desire to go ff at the moment, so I wouldn't be buying a lens with that in mind.
I wasn't a huge fan of the 17-35mm because it just wasn't all that good on my 7d. I didn't get anything calibrated, and didn't do any AFMA, so maybe having a better copy would have been fine, but I couldn't justify it at the time.
I have considered the 28mm f/1.8, but I'm not sure if that would be the best idea for me.