General Purpose lens for $1,000 or less?

[neuroanatomist]

This is why I'm leaning towards the 15-85mm f/3.5-5.6. According to the review, the IQ is comparable to the 17-55, but you get the extra reach. Any thoughts on the two lenses?

Don't get the 15-85mm, because:

I shoot mostly landscapes and portraits, thinking about trying to do some senior photo shoots

Once you get above 60mm on the 15-85mm lens, you have an f/5.6 lens. For portraits, the desirable out-of-focus blur you want will, for lack of a better word, suck at f/5.6. You'll need f/2.8 (or less, which is why I mentioned the 85mm f/1.8!) to effectively isolate your subject from your background at these focal lengths.