I did the mac and cheese recipe from the Deceptively Delicious book - using pureed cauliflower. I don't usually make mac and cheese, and certainly not the hard way, making the sauce and all. I thought a few times that I was going to scald or curdle the milk, but it turned out fine. Actually, ultimately, the thing tasted sour. And it finally dawned on me that it was the cream cheese in it. Who puts cream cheese in mac and cheese? (I hate cream cheese) Yuck. Jake, my eater, couldn't eat it - he said it was sour. He really was trying, but was making awful faces and taking these bites and grimacing. He's such a good boy, trying to eat it. :-) Ryan wouldn't even touch it. He chose the broccoli over it! Dont' get too excited. He ate the smallest piece of broccoli. I figure that was a victory - why make him eat sour food?
The verdict: the cauliflower puree doesn't ruin mac and cheese. It thickens it, so I would try it with a different recipe. If you like cream cheese, if you like sour - then go for it.