These lures seems to be a hot item as of lately ever since the Double Cowgirls as I can remember.  There's just something about them.  How they have greater water displacement compared to a single blade inline spinner.  The way how they make a subsurface swim to make a wake and crest disturbance so uniquely.  Just awesome.

Although they do catch a lot more wind on the casts...

You've reminded me I have a box of musky and walleye inline spinner lures somewhere. I've only used single bladed spinners for crappie, bass and eyes. When EBay first started I "won" a collection of tackleboxes full of old odd tackle, and got a whole lot extra loose baits thrown in. "Christmas in July". I figure the seller decided to get rid of everything while at the deal. Included were some double-bladed inline spinners in several sizes, but not the wing type I see for sale these days. They were all willow and colorado blades, some counter-rotating, maybe all that way. I never tried one out, but imagine they would be great for bass too.

Jim