I have done both plans with a break inbetween. I just cant get on with PPs, at one stage i lost no more than 0.5lb a week for 3 weeks, then went on a caravan break where I took my iPhone/iPad with me and bought prepointed food to keep me going, so no cheating occurred, did a little bit more walking during the break and ate fruit (which I dont usually do) and i stayed the same!!
I must admit I did get on better with the Discover plan, but even that, I managed to fall off the wagon. I am now following the Scottish Slimmers Plan (a bit like Discover, only you dont eat as much), and have lost 11.5lb in 6 weeks, including about a 6 day slip up, lol!
Give PP a go, after all, you will never know unless you try it first, there are a few people who have extremely good losses the first few weeks whilst others (like me) dont, lol!