Dogs: Harness, Collar or Head Collar?

[Kalarvely]

Just curious, dog owners... Do you prefer a harness, flat collar, or head collar (like a Halti or Gentle Leader) for your mutt? And why?

My staffies always had Halti head collars - worked like a dream: instantly stopped pulling. Although my last staff also sometimes had a lead on a Lupi harness which, whilst not as good as the head collar, was good enough to stop him pulling.

My little terrier has a harness but she walks with a loose lead and is not a puller.

I have seen these new (new to me) Halti harnesses with a double ended lead that fastens at the chest as well as the back - which look good, though and wonder how they compare to other things...

What do you use.have you used in the past? And why?