[seanica]

That's true, but sometimes

1) you don't have access to that type of information because either it is unknown, or it is unpublished.

2) you have no choice because the people selling your product have already made a promise to the customer.

[mmastrac]

Exactly. Or you know that the iPad has a ton of HTML5 media limitations when you start, but when you actually start working with <video> and <audio>, you realize that you're not only fighting stuff like "click to start playing", but there are bugs where seeking doesn't work if you try to do it too soon after loading (undocumented), the system AV player will crash from time-to-time, requiring you to reboot the device (undocumented), etc...

The iPad's browser is alright on static sites, but once you start pushing up against the limits, it becomes a very crashy, buggy platform like IE6. It's still lightyears ahead of the Android Browser, and a bit ahead of Chrome for Android, IMHO.