tiffanieh,
There are so many terrific skills wound within studied dictation that I think it is definitely worth a try.

The kiddos have to capture the whole image of a sentence or a passage in their minds, looking at the sentences as a whole as well as capturing the individual words and their parts. This really trains kiddos in the habit of seeing correctly spelled words within the context of writing, which afterall is the ultimate goal of learning to spell! We want kiddos to carryover their spelling to their writing, so practicing spelling words within the context of writing sentences makes sense.
Studied dictation also forces kiddos to strengthen auditory skills as they listen to the parent read the passage only once. The kiddos learn to listen for the purpose of repeating perfectly from a single reading. Prior to writing, they then repeat back what the parent said, which strengthens the skill of holding a phrase or sentence in the mind long enough to be able to repeat it back without error and then write it.
After writing the phrase or sentence, the kiddos then proofread their work before checking it against the model. This is a terrific way to form the habit of proofreading their written work!

It truly makes good proofreaders out of kiddos over time. Last, they check their own work, training them in checking their work against a correctly written model. They become precise checkers with continual practice.

Plus, when kiddos miss a passage, they mark any mistakes on the passage and immediately correct the mistakes on their own copy. Yet, another skill practiced is immediate correction.

And, the following day when the child must repeat a passage, he/she pays much closer attention to whatever was missed the day before, in essence finally causing the incorrect mental picture of a word in the mind to be rewritten or mentally corrected (replacing the old incorrect image with a new corrected image).

This is the mental work that must be done in order for a poor speller to fix his/her poor spelling habits. It is also something the good speller does naturally.
I must honestly admit that studied dictation is one of my all-time favorite CM skill builders. It has so many skills wound within a 5 minute lesson, and it pays such big dividends in so many ways in the long haul.

With my oldest son, we began studied dictation as a third grader. He is still doing studied dictation in high school; but he is an excellent speller, proofreader, and writer. He has never completed a formal spelling program beyond grade 3.
My second son is an 8th grader this coming year, and he has never had any formal spelling beyond what is in the HOD guides. He has also done studied dictation since grade 3. He is a terrific speller, proofreader, and writer as well.

My next little guy will be in 4th grade next year. He was new to studied dictation this past year, and he was not a naturally great speller or writer. However, I will tell you that he has made huge leaps in this area through using studied dictation.

I will warn you that dictation is a slow burn, so if you embark upon using this method plan to give it at least a full year to begin to see the fruit.

Once you do though, I think you will really be pleased!
Blessings,
Carrie