Hi Dea,
I really don't have much experience, but I do prefer doing the low-carb method (South Beach, Atkins, etc.) I am working on losing my baby weight, and it's been tough going after 30. I suspect that I do have insulin resistance - my numbers are on the high side, but not high enough to be labeled 'insulin resistant.'
I read South Beach and am currently reading Atkins, and both emphasize the importance of the Glycemic Index when chosing carbs while trying to lose weight. The Insulin Resistance Diet you're asking about sounds like a compromise between the two. Either way, I think 30g sounds reasonable. To check if you're losing weight, see if you are in ketosis. If not, cut back to 20g and see if that speeds up your progress.
I agree that living on that few is limiting (and I don't want to eat that way forever). Some people have no problem with it, some people really miss their fruit or pasta, etc. Frankly, I feel terrific. I have more energy, my quality of sleep has improved, and my mood swings are much better. My hormones have been so topsy-turvey since I had a baby, and I feel 'leveled out' now.
I hope that helps answer your question. The Insulin Resistance Diet sounds like a reasonable plan - I'd give it a shot