I recently found http://brookdalehouse.com/charlotte-mason-method-and-write-from-history/ and I will be using it this year. It is a gentle method without all the repetitiveness of FFL, which I used last year for both my kids.
The biggest draw I had to this particular one is that the grammar can be as easy or complicated as you choose or feel your son can handle. I like the color coding and I think the working with each part of speech for a month will help transfer the info from short term to long term memory, which is a big thing for my son. He can handle short term memory things easy peasy, but ask him to do the same assignment a couple weeks later and he will look at it ans say he has never seen it before! Being that grammar is so boring, he tends to let it go in one ear and out the other…LOL
Not trying to turn you away from the other options, just wanted to offer one that I happened to stumble upon.