I have a conventional rake, with a thumb works well. Probably wouldn't be so usefull without the thumb. Came fairly worn out with my machine, added adaptors and replaceable teeth to give a bit more length and surface area for raking and prevent cutting through stumps. Watching youtube, looks like the scooping style would work better for separating the dirt, but that always depends on the conditions, and how much time you want to spend. I find, with the right conditions, dropping the stumps works quickly and well enough to separate the dirt. I could be wrong, but it appears the conventional rakes are built a bit more robust. and possibly more reliable with heavier use.
Best of luck in your choice