After some deliberation (and the pending arrival of a bonus check at work) I'm seriously considering an upgrade for my general-purpose zoom. The Tamron 17-50 f/2.8 has been a good lens for the past three years (even with a warranty claim) but I would like to add image stabilization and silent/full-time focus, which probably means Canon and Ultrasonic. I'm shooting on a 7D (crop-factor).
Most of the L glass in the wide-zoom range is some combination of too expensive and/or lacking IS, and I have no aspirations of going full-frame, which means the EF-S 17-55 f/2.8 IS and the EF-S 15-85mm f/3.5 IS are my most likely options.
The main differences I can identify:
- The 17-55 is larger and slightly heavier, but offers f/2.8 and uses a single-sleeve zoom extension (probably more reliable in the long run).
- The 15-85 is smaller and slightly ligher, only offers f/3.5 but is alleged to be extremely sharp. Also, it's about half the price.
That noted, I'm leaning toward the 17-55 but wanted opinions and/or alternatives. My limit is going to be around $1100 (which includes an allowance for the resale of my Tamron), meaning any "L" options would have to be readily available in the used market.