The rock hound is nice when working with rocky soils, but it won't pickup anything large. Also if you have high green grass growing where your leveling it can wrap around the drive. It's not a problem and I used to actually use one with the intention of weeding out an area. Rock hound won't get all the green grass out but does a good job. If skilled you can grade with one just about as good as with a harley rake. I've only used them on skid steers so with the rock hound your going backwards while with the harley your going forward.
The Harley rake can make a bad grading job look great, but there's the extra work involved with getting rid of rocks. It also can do a great job clearing an area with weeds and grass that's still green. When done we used to then backgrade everything with the harley rake as it leaves a great finish for planting, but be careful when using one if it's going to rain. The harley rake really loosens up the soil and it can cause washouts.
If your good with a loader or skidsteer you can do just as good a job without one, but if you have no loader skills then the harley rake is for you, it does a good job leveling as well when it vindrows filling in low spots.
There's also a german made rake that I can't recall the name of that actually buries the rocks pretty deep. I saw a demo once in the 90's and it actually did a great job but where we lived there is so much rock, just a few inches down, that it would make buring it difficult.
Good luck with your choice. Also a word to the wise if using straw rent a straw blower or if you have kids have them do it.