It's also about Quality over Quantity.
There are a very few well done android tablet apps. The rest are utter and complete garbage. Oh, you can can run them and do what they're meant to do, but the android ecosystem makes it hard for programmers to deliver the quality you suggest it has. Most people still use a ton of android apps developed for phones and smaller platforms - it's one of the reasons the medium sized tablets are doing so well, the small apps don't look absolutely horrible on the 7" display in the same way they do on a 10" display, and app developers just aren't developing for the 10". Now that the kindle is out, a lot of developer are specifically targeting the medium sized screens, but it's still a very limited ecosystem.
In this case the iPad has both quantity
and quality on its side. The android tablets, not so much in either case. If you only do a handful of things with it, then you can probably find the 20 apps you need, and they will work well enough. But as long as you can do what you want, and still save yourself $250, then it might fit your needs.
There are other significant advantages to the iPad, but it seems like one of the requirements here is low cost, and for that you have to make compromises, especially in ease of use and stability. One of the biggest reasons I still shy away from android devices is that manufacturers completely drop support and software updates after a year or so. My iphone 3gs and ipad gen 1, both many years old, are running the latest version of iOS and are still supported by Apple and 99% of apps. My wife's android phone, nearly 3 years old, is still running 2.2 - but only because she spent two days hacking it on there because it came with 1.1 and the manufacturer dropped in mere months after introducing it. The android tablets we have all run 2.2, and of course the manufacturer isn't interested in upgrading them - they want you to buy their latest and greatest if you want honeycomb. Of course they will drop that in a year or so.
As a result most app developers target older versions - 2.2 is still the largest installed base of android devices, and it's fully two years old. They don't make use of the latest hardware in the android devices because it's not available in 2.2. Developers who target honeycomb and later get a lot of cool features, and a teeny tiny little slice of the market.
Amazon purposefully designed their tablet to be incompatible with the google android ecosystem so they can control a little bit of the content model their customers use. You can hack around it if you like, but not only is there natural fragmentation in the android arena, there's purposeful, and even malicious, fragmentation. But the real problem is amazon didn't even start with the latest version of android - they started further back with an older version. They've already chosen to ignore the latest features available specifically for tablet use. Rather than small tablets, most of these devices are really upsized PDAs in terms of usability.
The android tablets aren't competing with the iPad. You buy one when you've decided that either 1) you don't want a large tablet and/or 2) when you don't want to pay the price for the larger tablet. If you don't have anything against a big tablet, and you can afford it, then the iPad is a better choice, and is most assuredly worth it.
