I don't know about ketostix. I have seen a lot of people on here say that they are kind of useless, since we drink so much water on this program that they might not register any Ketones at all (since they would be so diluted). So I have never tried them. I also just didn't want to get myself into the habit of being dependent on them to tell me if I am in ketosis, and freak out if they said I wasn't. I just know I am losing weight and not hungry all the time, so I assume I am in ketosis. And if I am not... it is working anyway.
I have tried a few proti-diet and healthsmart products from Nashua, just to mix things up a little. You have to be careful and make sure it doesn't have any of the sweeteners that we aren't allowed (Some of the delicious sounding flavored hot chocolate drinks have aspartame), and make sure to compare labels to figure out which items would be restricted. I love Healthsmart's bars (The caramel crunch tastes like a 100grand bar), and Proti-diet has some good soups. I like the chicken noodle and beef vegetable. I wouldn't replace all my food with them, though, as they don't have quite as much protein and the food we eat on IP is nutritionally designed with this diet in mind, whereas I don't know if these are. They are nice for a change a few meals a week though.