First, they were the greatest things since the invention of bacon. Now they're being declared disastrous failures.
Are they hot? Or not?
When the iPhone 4s shipped October 15, and reviewers and pundits got to try Siri, it was hailed as the greatest new technology in a generation.
The New York Times' David Pogue called Siri "crazy good, transformative, category-redefining," "crisply accurate, astonishingly understanding" and "mind-blowing." Other prominent journalists were saying similar things.
Fast forward to today, and the honeymoon is clearly over. "The Siri backlash is here," said the Atlantic Wire blog. Siri "just doesn't work that well." Other commentators called Siri a "half-baked" technology with too many "rough edges" to be useful.
The problem has been magnified for many users by the fact that Siri servers are often unavailable, sometimes going offline for days at a time for some users. Even when Siri is available, server overload causes delays in the response time.
Server outages are the biggest threat to the success of Siri, because the opportunity for people to develop the habit of using it is slipping away. Many users formed a strong inclination to use Siri in the first week or two of use. But frequent outages weaken the habit for many.
Some users say they're less likely to even think about using it, because it's down so often.
When Google+ came out in the summer, the service's many advantages, including circles, multi-user video chat "Hangouts" and super-clean interface motivated many to declare it vastly superior to Facebook, despite flaws and limitations.
TechCrunch's MG Siegler called it "so well designed that it doesn’t really even look like a Google product."
Wired.com's Sheril Kirshenbaum was "quite impressed" by Google+, saying it "looks great" and that Hangouts were exciting.
Writing for TIME magazine, Harry McCracken called Google+ "intuitive" and "playful" and pointed out that many of Google's harshest critics really like Google+.
But then the backlash hit, mostly centered on a single report by an advertising company called Chitika, which published data showing a radical increase in users when Google+ opened to the public, which subsided after a few days.
That report triggered a rash of stories in which journalists compared the spike to the post-spike traffic and concluded that Google+ traffic had slowed.
Slate's Farhad Manjoo wrote a widely shared opinion saying that Google's opportunity to compete with Facebook had already "come and gone," using as evidence his own perception that the stream from people he circled was "dreary," that Google executives didn't seem to be using the service much -- and also the Chitika report.
Amazon's Kindle Fire
A similar phenomenon happened with the Kindle Fire ebook reader. Early reviews pointed out that while the Kindle wasn't as slick or polished as Apple's iPad, the low price of $200 made it easily worth the money. Besides, they reported, it was a cool device and they really liked it.
Mashable's Lance Ulanoff called the Kindle Fire a "worthy" gadget that "simply works." It has a "fully thought-out ecosystem" and that "reading on the device is a joy." Despite some misgivings, Ulanoff called the Kindle Fire "an excellent and easy-to-use content consumption device."
Other early reviews were generally favorable, especially in the bang-for-the-buck department.
But more recently, the Kindle Fire has been eviscerated, most savagely by user interface expert Jakob Nielsen.