You're familiar with the shortcomings of the 17-40mm f/4 L, so I won't go into those here. Suffice it say when I compare sharpness and clarity to that of my 50mm f/1.4 and 70-200mm f/4 L, it comes up a little short.
Here's my question to you: If I were to replace it, what's your recommendation, keeping in mind a similar focal range to complement the two other lenses I mentioned? I'd like something under $1,000 USD, without regards to what I could get for my 17-40. I'm willing to consider an off-brand lens, if it meets all of those guidelines and still outperforms the Canon I already have. Oh, and I shoot with a 5DmkII, so I'll need to stay away from anything EF-S.
Thanks in advance for your suggestions.