I'd personally choose something like a 24-70 f/2.8 or the 28-75 f/2.8. Sacrifice range for speed and quality. No 18-Xmm lens can come remotely close to those in quality, and the fast f-stop is especially useful. Another thing is that those 18-XXmm lens are almost always (can't think of an exception) built for an APS lens, which is fine and thats what you have. But, the 24-70/28-75 being built for full frame will give you a sweet spot advantage, which is a major optical benefit. At 18mm, APS lens have pretty typically terrible border performance.

If the wide matters more than the telephoto to you, Tamron makes a 17-50 f/2.8 that has most of the same benefits (except its also an APS lens). Very fast, excellent quality.

In my opinion, f-stop range matters more than focal range.

Hope that helps.