Works great with AT&TCustomer Rating:
After helping a friend install an HP 6380 (the functional equivalent to the Canon MP620) with an AT&T DSL wireless router, I decided HP didn't have their act together... I had to dig around in their website to find an obscure workaround for the Blue Screen of Death (and totally frozen controls) on the printer, caused by trying to install to that particular router.
This Canon installs gracefully with that same router, although it initially needs a USB connection to the computer during the setup (which HP doesn't). The Canon starts up more quickly, does much less clicking and whirring after a print job, and appears to be essentially the equal of the HP in performance and print quality. A "manual" alignment step is recommended (get out your magnifying glass), while it's supposedly automatic on the HP (I'm not sure how), but it was simple enough. The Canon control panel might not be quite as intuitive as the HP, but if you like a clean, uncluttered look (or have very small children), the closed front and lack of external buttons will appeal. The Canon also has a rear paper tray for a straighter paper path for heavier stock and photo paper, in addition to the enclosed front tray for standard paper (which doesn't let you easily see your supply). And the MP620 has generally been available for less than the HP 6380.
If only I hadn't found that HP workaround... We could have returned the 6380 as defective (it was frozen solid), and gotten her an MP620!