• Biggest reason: I couldn’t find a comfortable way to hold the darn thing. The narrow bezel requires you to hold the device at its edges, or else you’ll turn pages or do something else on the touchscreen you don’t want to do. Also, the on-off switch is on the bottom, so if you use part of your hand to support it from below you’re always in danger of turning it off. So I could only read by holding it quite delicately in both hands. My Kindle 3 is far easier to hold. (The physical keyboard actually helps in that regard: you can’t touch the keys, of course, but the surrounding space gives you more places to put your thumb. I can also turn pages on the Kindle 3 while holding it with one hand.)
• Along the same lines, the Fire weighs about the same as the much larger iPad, so it feels really heavy for its size. I couldn’t quite get used to that.

• The web browser sometimes worked quickly, but stalled out way too often. Also, the touchscreen feedback was inconsistent: sometimes I would touch and get an immediate response, sometimes the response would be delayed, and sometimes it wouldn’t respond at all. I was never sure how long to wait before trying again. (To be fair, I occasionally had this problem with the iPad too.)

• Navigating between programs is considerably slower and more awkward than with the iPhone or iPad. If I had anything even the slightest bit productive to do — adding a reminder to Remember the Milk, jotting down something in Simplenote, sending a quick email, even reading a document in Instapaper — I found it far easier to whip out my iPhone for the task.

• While it’s nice to be able to read in the dark or dim without turning on a light, I can’t read on a backlit screen for very long without my eyes starting to ache.

• I think the iPad screen is a great size for watching video, but the Fire screen seems too small to me.

In general, for reading the e-ink Kindles are infinitely better than the Fire, while for anything else my iPhone is better. I came to see, in just a couple of days, that I would simply never use the Fire. And it doesn’t make sense to pay two hundred bucks for something that’ll just sit around gathering dust.

It goes without saying that YMMV. I have a MacBook Air for work, a Kindle for reading, and an iPhone for general life management; I don’t see the need for a fourth device. (Which is why I also gave my iPad to my mom, even though it’s a far superior device to the Fire.)