Hello! To be honest, this is the best diet that I've ever been on. I've tried WW and my points value for each day were so low (19!) that I felt like I was starving and I got REALLY neurotic about what I was eating. I've also tried becoming a vegan a la the Skinny ***** books, but it really didn't work for me. Giving up meat was fine, but giving up cheese just about killed me, as well as making me feel neurotic, again. This is the second time I've been on the sonoma diet; the first time I lost 20 lbs. and kept it off for three years, but when I got married, my eating habits changed to reflect my husbands and I've put on about 12 lbs. We've been on the diet now for about 3 weeks: I've lost 8 lbs. and he has lost 12. It can be difficult to stay on the plan if you eat out a lot (many restaurants don't serve whole grains, but some do.) We've found that we're generally making better tasting food at home than going out.
As far as is it expensive, you will be buying whole grain breads, whole grain cereals, fresh veggies (frozen are ok too) lean meats like chicken breast, flank steak and all sorts of fish. I don't feel like I'm paying more for groceries now than I was before. The things you'll buy aren't really expensive, just a lot healthier.
I would've liked these foods as a teenager, but I really like veggies, so I guess it would depend on your kids taste. To me, this is one of the only diets that is really family friendly. Its not hard for everyone to sit down at the table and enjoy what they are eating whether they are on the diet or not, because really its just good food that happens to be good for you. As far as breakfast goes, I don't know that smoothies and powerbars are really on plan. We tend to eat either boiled eggs and whole wheat toast or kashi goLean cereal with skim milk. I'm not a big breakfast eater either, but if I boil the eggs ahead of time, it's not too much of a hassle.
I just bought the cookbook, the first time on the diet I didn't have it, but I think it is really making a difference this time around. There are a lot of recipes in the diet book, but the cookbook gives you A LOT of options, so I would recommend getting them together.
This was long, but I hope it helps. Honestly this really is the best diet out there IMO and it definitely works. Most days I don't even feel like I'm on a diet, which is great. I hope you try it!