I think Waldorf education is easily misunderstood. They do start academics later, that is a fact. But once a child reaches the grades, what is emphasized is the lesson content...various themes and stories which meet the child developmentally and feed their "souls". The academic work that accompanies this content should be tailored to the individual child. So for first grade, perhaps there is a child still struggling to write their letters well so they focus on that and another might be an excellent writer and could write a short summary to go with each story, etc. You wouldn't jump grade levels, you would just step up the work that goes with each main lesson, or take it down a notch if that's what the child needs. Waldorf can meet any child right where they are with exactly what they need, but the one presenting it has to bring it to them. By way of necessity, any boxed curriculum has to try and hit a common denominator...but if you are given the themes and the basic content, one can adjust it from there. It doesn't come without a good amount of prep time, though.
Personally, I like OM. I like to have a copy of the syllabus, at our grade level. I pull lots of ideas from it. I could never follow a boxed curriculum lesson for lesson, but I like that it gives a do-able foundation and I can go from there...adding things in, substituting other things. Also, we do so many other things...foreign languages, music, Waldorf arts and handwork, extra math...I wouldn't want something so time consuming and challenging that I couldn't add our other stuff on top of it.
Good luck! Also, try to get a copy of the syllabus used if you decide to give it a try. I have always bought them that way....for WAY cheaper!