We are currently taking an organizational skills class (for students, but the whole family attends). And the experience is overall positive.*
Of course, DD12 (technically 6th, working up through 8th) is also coming off of 2 years of semi-unschooling and is having to apply a bunch of these skills for the first time. It's been rough and there's clearly a big gap in terms of test taking, time budgeting, note taking, etc.
I think that 4th and 5th are the years where this stuff is introduced in a more systematic way in our district and she missed it by leaving public for homeschooling and the opportunity to accelerate.
Now that she's in a public school again (albeit an online one) we're noticing a lack of these skills. Academically, the material isn't hard, it's just the process of taking the right notes, double checking answers and not rushing and missing easy stuff, keeping track of work due and notifications and grades, dealing with the pressure of tests. In fact, she turned down some higher level classes (9th grade) that the teacher suggested, and we're glad she did because so far her learning has all been in this executive skills area.
* Regarding the class... While DD has done some foot-dragging, I still think the class has been helpful. But we have had to approach it a bit differently with her. The class is not for gifted kids and I know she sees some of the exercises as overly simplistic and the pace somewhat slow. We just allow for a certain amount of doodling and let her express her thoughts regarding logical inconsistencies in the curriculum or areas of disagreement (politely and appropriately) with us and the instructor. The instructor seems to "get" her quite well and she's absorbed some tips and techniques seemingly by osmosis. The assistant on the other hand, seems to find her affronting somehow. But we've seen this before and don't let is get to us.