Sony mentions their patented CineFrame mode at 30 or 24 Fps. I don't think this is really a progressive frame mode - can someone explain, and also comment on how the results look ?

Here's a very thorough examination by Adam Wilt: http://adamwilt.com/HDV/cineframe.html

You may wish to exploit it as an in-camera "film-look" effect simulating film's gate weave or jitter, but if you want rock-solid 24p emulation, this isn't it.

Tkanks, Boyd. That was indeed an excellent explanation.

I would also check out Cineform's site:
http://www.cineform.com/products/SonyHDVSupport/CineFrame.htm

VASST also has some pictures of what it looks like:
CF24: http://www.sundancemediagroup.com/training/SonyHVR-Z1U_CF-24_cadence.htm
CF30: http://www.sundancemediagroup.com/training/SonyHVR-Z1U_CF-30_cadence.htm

I've used cineframe 25 and experimented with cineframe 24.

CF25 looks great, a little more stuttery than I used to get with 16mm but only 'coz I'm staring hard. CF 24 is definitely jerkier, especially on pans. you can clearly see the pull down pulse on steady moves.

Both are noticable softer than 50i. However CF25 downrezzed to SD is very sharp compared to DV, sometime too sharp, introducing rather obvious moire patterns and interlace flicker on high frequency detail.