I think that the problem is there are a lot of substandard textbooks and online programs out there. I don't have a whole lot of experience but so far what I have seen haven't been terribly bad. Having said that, our district develops a ton of curriculum to be used with published textbooks. In elementary school, the math curriculum is heavily subsidized by our district's own curriculum so that less than half of the materials came from the textbooks. Two years ago DS used a relatively older (Pre-2000) version of McDougal Littel for "Pre-Algebra" titled Passport to Algebra and Geometry. I think that the newer versions of that McDougal Littel text is less GT oriented. The ordering of the units seem sensible enough. DS is currently using Holt McDougal for Geometry (Common Core version) but that is to be used with our district developed curriculum as well. This particular text was chosen after a lengthy piloting process involving three or four different textbook companies so the hope is that a good choice was made but who knows. I have glanced briefly through the Geometry text and it looks okay but then I like pictures and colors.
As for multiple approaches, I am actually heavily in favor of exposing students to them but not forcing them to use every approach. The best math teachers regularly present multiple ways of the solving the same problems. One way that I survived too easy math courses was because the teachers always challenged me to come up with a different method of solving the problems than what was just presented.
