Overcrank with a little help from the nanoFlash
 

I'm amazed at what the combo of Optical Flow in Compressor and nearly uncompressed 1080i (via nanoFlash) can achieve.

Here is the raw 1080i nanoFlash clip I posted previously, but this time deinterlaced and turned into 60p and then frame rate conformed to 23.98p for 2.5x 'overcrank' slowmo.

It's actually a full 1080 clip and good h264 compression, but might stutter on some computers.

125 MB, 25 seconds

http://files.me.com/mrbarlowelton/anvenw.mov

I think you're always going to get better slomo with 720/60P rather than de-interlacing.

Steve

Obviously progressive is preferable, but in this case I've been surprised at how good the conversions can look with really clean, full-raster 1080i footage.

Did you notice how well the h264 held up on the shot? That rushing water is hard to compress but because the original shot is artifact-free, the final distribution level encoding can be nearly free of the blockies too.

To be honest, I never look at stuff on the net as it never really shows anything!
I can imagine that good, low compression interlaced stuff can look go de-interlaced, I assume it depends largely on the programme (ie algorythm) used to do it - what did you use?
AFAIK this is how the Sony F355 and the new PDW800 do slomo, de-interlacing in-camera, and it does look good, even with their 50 mb/sec compression.
Steve