I avoid both SOs and DDs wherever possible, though I must admit I'm more fearful of DDs. My problem with them is that the recipient seems to be able to adjust the amount of the payment without providing any evidence of the account holder's consent, which I don't think can happen with an SO.
Anyway, a few years ago British Gas tried to persuade me to sign up to a DD. I said I'd agree, provided they did likewise, giving me unlimited access to British Gas's bank account, just as they'd have unlimited access to mine. Thanks to the DD guarantee, I explained, they'd have no worries about any fraudulence on my part, just as I'd not have to worry about any mistakes they might make. Amazingly, they declined.

7LM
edit, PS - I couldn't agree more about CC continuous authorities being the work of the Devil, and all to easy to fall victim to, particularly when applied to on-line purchases, such is the impossibility of actually reading the entire T&C when you purchase on-line.