You're still wrong on that, but what do I know. All they're doing is shortening the ROM to a more favorable leverage.
tried your variation of the leg raises, not sure which ROM you suggested if it was just to 90 degrees, or legs to bar but i did both and ended up going all the way to the top for my sets, along with a set of cable crunches 4 x 12 with quality form.
the leg raises were more difficult than with straps which is probably good since im getting to nearly 30 reps per set before fatigue. I felt like with the leg raises tho i had to have all of the force at the bottom of the rep and basically lower with control on the way down. Not sure if that is due to lack of ab strength (please let me know what you think) or just the way the exercises should be done.
either way my abs were definitely worked hard and i will continue to try your method until i find what works best for me, possibly going back to the straps for more slow controlled MMC reps every other workout???
thanks for your time Rodja