I can't really tell too well, given the small size of the photo, but the new slider looks to be a good 2mm more narrow than the old one. Still looks pretty angular to me, though....BUT, the comparison pic you posted to the Todd's is nearly identical in color and size.
An improvement to be sure!
Oh, and I do agree there's a possibility the sliders' placement may have contributed to the seat damage, too. Once I put the rect. Loops on, the straps pulled toward the front of the jacket, moving the loops more to the front, too...and away from my back.
The sliders, on the other hand, facilitated a strap pull towards the BACK of the jacket, situating the slide buckles more towards the back, as well...and, consequently, right where the back would sit against a car seat.
And probably, the sharp edges against leather seats was a factor, too...cloth seats may not have experienced the same issues...
Hopefully, the smaller sliders will be the needed improvement to that issue.
Indydawg