I lost 6lb in my first week.
I haven't really had that many HUGE losses, although I regularly loose 2-4lbs, I'm not one of those people who manage 6-7lb losses.
Slow but steady wins the race! I could have lost much quicker but I use flexible syns fortnightly or so, and go through about 80 syns on a night out when I do! Those weeks, I only loose 1lb or so.
Loosing 3lb a week and 4lb every now and again, achievable for most men, is a stone a month: a realistic target on SW for a bloke with quite a bit to loose.