One of the best components of Forester is that you can teach yourself from the book. It is so step by step but it does get wordy at the beginning and focus on definitions, most Algebra texts do. I hate to say it, but most math texts are hard to do that with and really get the concepts not just memorize steps.
I don’t know of a high school text that works like Mammoth where she shows rather than tells. Disclaimer- I haven’t used them all.
Math U See, maybe, but if he went through Mammoth 7, Math U See Algebra will feel like a step or 2 backward.
Videotext likens math to a language right off the bat and it is super expensive but two of my son’s really liked it. I tend to use it for the kid’s who are naturals at math and can then apply the concept anywhere. They have way less practice then would be needed for a couple of my students. My students who have used that program can for the most part do things alone.
I only have Jacob’s Geometry (not the Algebra) but it always seemed more word happy than Mammoth but maybe the Algebra is different. I have heard of kids who enjoy reading his text since he makes them fun but it isn’t like Mammoth.
If you are able to teach then maybe Jacob’s or Dolciani’s but without extra supports it may be better to do something with added videos for explanations etc to take on the teaching portions and something that assigns an appropriate number of problems. Most textbooks have way more problems than needed in general because different students might need extra practice with different types of concepts so they are there as extra practice. I find it can be difficult to pare a book down if you don’t know the material well yourself.
I know Maria says students should learn from a textbook but students in school get a textbook + a teacher. If your student is learning on their own you may want to look at a more supportive, made for homeschooling, type of curriculum. If you are able to teach him, then I recommend picking a book you personally are comfortable working with.
Oh and as a sidenote, the Math Without Borders lectures are good but boring. If he already hates the book then he won’t feel better about it after a lecture. 🙂 He is very detailed though when you are stuck. It is just so much faster for me to teach a concept because I can ask my students questions and therefore quickly skip over parts they know.