up res how? There is software that makes sd hd...but the difference between overcrank 720 and 1080 is so subtle is wouldn't be worthwhile.

If I gave you a 1080p version of Piccadilly Furs or Dungeness you would struggle to tell any difference at all! Perhaps only thinking it's 720 because it looks like overcrank. But there were loads of shots in my Kew Gardens film that were shot 1080p and then slowed down using Twixtor and also some normal speed shot in 720p that I forgot to switch back after overcranking

Thanks, and I'm happy to know real pros leave switches in the wrong position too!

regarding overcranking, does the practice burn more card real estate?

why overcrank when you can slo-mo in post?

Because the results are better. This one of the real pro features of the EX1

Doing slow motion in post is a cheap way of achieving the effect and the result is usually indicative. For example, I was watching (for what must be the 30th time, not kidding) The Fellowship of the Ring last night and there are a few shots in there that are tragically suffering from the obvious ugliness of doing the slo-mo in post, despite being done in Avid (for example, the shot of Gandalf right after Frodo is stabbed by the cave troll in the Moria battle scene).

AFAIK, by doing slo-mo in camera, via overcranking, you can get the same high sampling rate of the actual motion as an overcranked film camera. In post, it is more like artificially slowing playback speed.

The result of doing it in post is usually choppier motion, and a look of slowed playback speed. Contrast with in-camera which has smooth motion and a look of movement through a medium denser than air or, say, a lighter or absence of gravity (like astronauts in outer space).

There are plug-ins that allow for a better "in post" achievement of slow-mo, but you are likely to get the best results in-camera.

EDIT:
A great book, which everyone should read, is Herbert Zettl's "Sight Sound Motion: Applied Media Aesthetics" (ISBN 0-534-52677-2) It has great info about, amongst other stuff, the dimension of time in film and video. Many pros here will no doubt be familiar with Zettl's authority on the subject of production.

Do you know if anyone made A-B test comparison of 720p60 slowed down in post, vs 720p24 overcranked to 60 fps in camera?

I'm under impression that simply shooting 720p60, then Interpreting the footage as, say, 20fps in After Effects will result in the same smooth motion as in-cam overcranking - but without the limitations of S&Q mode such as no sound etc., thus leaving more options for post.