We have been using Tindall and Shi's America, a Historical Narrative, which seems to be too advanced and a little too difficult for the HS juniors I teach.
Readability is a major concern.
I am, of course, using other sources of information to make a choice, but nothing beats the experiences of sucessful teachers. I am somewhat troubled by the gist of the letter that sparked this discussion. As someone who has TA'd US 101, I liked the book and the way the teacher used it. Each chapter came with an essay packet that helped the students immediately digest what they read and also worked them hard on essay writing skills and DBQs for the exam. This worked very well at teaching the kids chronology and analysis and at the same time helping them master the exam format.