I had to vote hygienist, solely on the basis that, out of the various dental people I met last year, I think she was the best at dealing with me and my anxiety.
I had all my hygiene appointments unsedated (although some of the cleaning etc, especially my back teeth, was done by my dentist instead, while I was under IV sedation); and I still would prefer to go back for another appointment with her than to go, sedated or otherwise, to anyone else. I did really like my last dentist too, but if I'm forced to pick, it would be the hygienist.
(Sadly, this is all rather moot now, though, since I've had to leave that practice and so won't be seeing either of them again!

But I've yet to meet a hygienist at the new place, so could only go on my previous one.)
Anyway, basically my answer is about the person, not the treatment. Hope that doesn't skew your results! ...Actually, having said that, there probably are other sides to it - I left every hygiene appointment unsedated and in no pain, rather than doped up and with pain to follow (as after dental treatment). They were also shorter appointments. But the main factor is simply whom I feel safest with.