Here's my take on the matter:
Weight loss (neglecting water weight) is simply a matter of calories in vs. calories out.
However, we're interested in the type of weight lost, i.e. maximizing fat loss and minimizing muscle loss. This is a matter of nutrient partitioning, which is affected by both diet and training.
In the Ultimate Diet 2.0, Lyle says that he doesn't recommend UD2 for men above 15% body fat (something like 23% or so for women) simply because it's not necessary. If you're over 15% body fat then any non-idiotic hypocaloric diet will work, non-idiotic meaning you satisfy 1g/lb. of protein and enough fat (whatever "enough fat" entails). You don't need to use fancy diet tricks to try to improve nutrient partitioning, because with that much body fat most of the weight lost should be fat.
Simply put:
If you're not losing weight, you're eating too much.
Conversely, if you're not gaining weight, you're eating too little.
This is the bottom line, regardless of whatever macronutrient ratios you use. However, macronutrient ratios do play a role in determining whether it is muscle or fat that is lost/gained.
If I understood right, Hardrock is 30% body fat. In that case, any non-idiotic hypocaloric diet should work, and it should be effective for preserving muscle. Keyword "non-idiotic."
Totentanz, whose body fat is lower, did well with a PSMF but might have done poorly with a more simple, traditional diet because at his BF%, partitioning becomes more of an issue.
That said, I don't know much about PSMF. About all I know is that it involves low calories, with a good percentage of them coming from protein. Perhaps if Hardrock wants to lose weight FAST then the best way to do it would be a PSMF. But what I said before about calories in vs. calories out and nutrient partitioning would still apply because a PSMF would simply allow him to create the greatest caloric defecit while maintaining good nutrient partitioning, resulting in a lot of weight loss with most of that weight being fat.
So that's my side of the story. Now I wait for Aaron to come along and either reaffirm it or tear it to shreds.