I can only speak for how I found it - in a word - boring! The food choices are in theory quite wide but my imagination ran out after about day 5 and then went into repeat menu mode. Also I started to have what are politely called 'transit issues' after about day 5 as well. And I was missing my vegetables, which I love!
I'm not sure its wise to go for longer than recommended for the amount you have to lose. I suppose you may lose more in that first attack phase, but the difficulty a lot of people have is that the weight goes up again immediately they go onto cruise. Its to do with water retention and the veg, I think.
Think you probably have to regard it as a marathon, not a sprint!