Agree on the last point -- at least, for Taiwan. In fact, those idealized graphs caused me a bit of a headache early on. Native mandarin speakers in Taiwan tend to drop the end of the 3rd tone, so it falls slowly then holds at the bottom for a minute, then rises slightly or even just cuts off.
Comments
http://www.mdbg.net/chindict/rsc/audio/voice_pinyin_cl/shi1.... (shī)
http://www.mdbg.net/chindict/rsc/audio/voice_pinyin_cl/shi2.... (shí)
http://www.mdbg.net/chindict/rsc/audio/voice_pinyin_cl/shi3.... (shǐ)
http://www.mdbg.net/chindict/rsc/audio/voice_pinyin_cl/shi4.... (shì)
For the falling-then-raising (shǐ) changing the "shi3" to "chi3" in the URL gives a better idea, I think, for what the inflection sounds like.
Agree on the last point -- at least, for Taiwan. In fact, those idealized graphs caused me a bit of a headache early on. Native mandarin speakers in Taiwan tend to drop the end of the 3rd tone, so it falls slowly then holds at the bottom for a minute, then rises slightly or even just cuts off.