Hi catch - I did LL earlier this year, and it really really works! I lost 2.5 stone in three months, then another half stone in a month. (BMI went from 32 to 26).
I did LL for about six weeks, and found the counselling sessions I did very helpful. But then I got pissed off with how expensive it was AND that they do automated card payments which I didn't realise (I thought I'd paid for a 2 month block, but they kept taking my money!) so investigated and started with Exante, which is much cheaper and has much nicer food, IMHO. (I really struggled with the LL food - all fairly grim).
It is tough, I'm not going to lie, but it is probably the easiest strict diet I've ever done, and much easier to stay on track - there is NO scope for cheating/not counting - I just ate their meals only and nothing else except water and black coffee passed my lips. And the joy was how quickly the weight fell off - which made it totally worth it.
It's now six months since I stopped and went back to normal eating, and I'm now at BMI 24.5, and have a whole new attitude to life and food. I wish I'd done it years ago.
I think it's a really good way of doing things if you are obese and want to lose weight quickly, and are prepared to be really strict with yourself.
Its very similar to the Fast 800 in terms of effects and physiology, (you're on 800 cals a day on LL) - Fast800 is possibly a bit cheaper but in terms of convenience and brainpower, I found the meal replacements so much easier (see above re calorie counting).
There is a Fast800 support thread somewhere which was really helpful to me.