For me Contour Power grips feel softer than Vise-Grips but only by a very tiny margin. I use both interchangeably. That said, Vise Grips are slightly larger for same numeric size than Contour. The 25/32" Contour fits my middle finger while the 25/32" Vise-Grip is too big. I use a 49/64" Vise-Grip. (That is another advantage of Vise-Grips: they come in 1/64" as well as 1/32" of an inch. Contour only come in 1/32" sizes.)

Also, to the feel, different colors of each have slightly different feel. A black Vise-Grip seems to feel slightly firmer than the transparent or a yellow Vise-Grip. I have preferred the transparent Vise-Grips for they seem closest to the same texture and softness that Contour grips feel to me.

I can't comment on Turbo Grips as when I was first trying them, I never liked their feel and never used them thereafter.

I believe some manufacturers so intentionally make different levels of firmness/softness in their finger grips. I don't recall which ones.