We started set nap at 12 at around 11-11.5 mths (to prepare for daycare) and set bedtime we should have done a long time ago but only started around a month ago (14 mths). It has helped immensely with our wake up, although he's still inconsistent, it's much much better - as you can see from PP it really depends on the LO and what works for them. Finn tends to be like babybarr's LO. Finn is also in the low sleep needs category, or he's average sleep needs but he THINKS he's low needs, either way we can't get too much sleep into this kid not for lack of trying...
We love the set naptime here, after 12 mths of battling naps, he finally settled into a great routine, goes down without a fuss and normally knocks off 2-3 hours. He's always had short nights, occasionally we will get a 10.5 hr night but normally he's 10 hours or less. Cutting the nap back hasn't helped for us YET, but there is always hope :-) We will keep that in our back pocket for future. We let him nap as long as he wants.
If he's ill or what not we always have the flexibility to adjust our times, but we stick to set times as much as possible even if he's tired, because it's the only thing that seems to work in our house at the moment. An earlier bedtime is now causing an earlier wake up for us and with a chronic EW you don't want to go there.