I've had good success with them. Right now I just have the Seagate set. I know it's not as refined a tool as HDDSurgery is, but still works at lifting the heads and safely pulling over the platters without touching.
I was quite surprised how well they hold in place. Only thing I'm not thrilled about is that pulling it out it sometimes has a tendency to pop out quickly dropping the head onto the platter faster than I'd like. But, you can definitely work with it.
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