I have a rather big JSON string to parse, and decided to make some tests with varying amounts of data. For all my tests the native JSON class is from 8.5 to 12 times faster than the TinyJSON class included.

Have you made any further test? Different environments can give different results, although I'd be surprised if TinyJSON were better on an actual device.

I've removed TinyJSON, although I see ExtendedMadness also uses it and for it I use the SWC.

Read a comment regarding the reason behind TinyJSON:

"I’ve based MadComponents only on core AS3 classes, and no AIR-only classes. I even made my own JSON class rather than use the one recently introduced in AS3. I’ve done this so MadComponents can be used in the browser, desktop, or mobile – or authored in older IDEs, or non-Adobe IDEs."

I guess that comment is not valid anymore, as it's not an AIR-only class, Flash 11 penetration rate is bigger, and I'd say most IDEs support it (Flash CS5+ can be updated to support it, although it's bothersome for AIR 3+ mobile projects).

tI think the comment is still valid if you're writing apps for BlackBerry devices.