amazon out; b&h in / tamron knocking on the door

Talked to an Amazon customer service representative last night. She denied they ever had the Canon EF-S 17-55mm f/2.8 IS USM in stock, and that if it had shown up in stock on the website that was a mistake, and that they had no idea when it would be in stock. Amazon is just hopelessly disorganized at this point, at least when it comes to photographic equipment. I responded that they've lost a customer of photography equipment permanently.

I cancelled the order and put in an order at around 2am PST for the same lens at B&H (large camera store in Manhattan). Result: it was shipped out 16 hours later. It cost about $35 (3%) more than Amazon, but if a non-defective lens arrives on Tuesday, it'll be well worth it.

Now the only hitch is the glowing preliminary report from Klaus Schroiff of PhotoZone about the Tamron 17-50mm f/2.8:

"Forget the Sigma 17-70, Sigma 18-50, Canon 17-85is and maybe even the Canon 17-55 if you don't need IS. A clear winner."

"High distortions at 17mm"

"vignetting is comparatively moderate at all focal lengths. In absolute terms it could be better at 17mm."

"very high CAs at 17mm at large aperture settings"

The Tamron is about $880 cheaper than the Canon, so I'd be willing to put up with quite a few comparative deficiencies. Plus, the Tamron appears to be lighter and smaller, and has better bokeh and a closer minimum focus distance.

One interesting early report involved a comparison with the Sigma 18-50mm f/2.8 in which the Sigma was sharper in the center, but much softer in the corners and overall yellower than the Tamron. That same report mentioned repeated Err99 codes with the Tamron attached (the user had never gotten that error before), and occasionally unreliable focus.

I'm sorely tempted to order a Tamron 17-50mm f/2.8 as well and do a head-to-head comparison to make sure I'm not spending $880 more than I need to. On this class of lens, I'd be willing to pay $50 more for Ring USM, $300 more for IS, $50 more for an extra 5mm at the long end, and maybe $100 for the compatibility advantage of a first-party lens. On the other hand, I'd pay $100 for the Tamron's lower size and weight, $25 for the slightly better minimum focus distance, and the included lens hood saves another $30. Thus, if the image quality were comparable, the Tamron represents about $535 in savings.

Basically, the Tamron needs to be at about 90% as good optically, and avoid any show stoppers, to come out on top. Show stoppers would be: repeated error codes, inaccurate autofocus more than a small fraction of the time, blurry corners at 17mm f/8 (like the EF-S 17-85mm f/4-5.6 IS), build problems affecting performance.

Overall, looks like it's going to be a close race.