primarily seen in the difference in weight. The newer brown 8" coil is heavier.
As for performance in the field? Well, I am going to say yes ... there often was/is, and more often than not it is in favor of the older white 8" open-center coil.
I used to use the Royal Sabre and original Eldorado and original Bandido a lot, mainly with the white 8" open-center coil and my favorite, the 7" concentric coil. I used the white 8" "donut" coil in more open areas and when hunting in shallow water.
When the Silver Sabre II and Bandido II came along with the brown open-center coil, I used them with my older Tesoro's and Pantera, making a point of doing some side-by-side comparisons with both the white and brown coils. The difference in weight was easily noticed, and the thinner white coil felt better.
As for depth of detection and handling iron trash, I will say that probably 8-out-of-10 times I ever compared these two 8" coils afield, the white coil came out on top. That means that perhaps 2-out-of-10it was either a draw or maybe the brown coil seemed a touch better.
If I had my choice today, I would take a choice condition/working original Eldorado and/or original Bandido and/or Pantera with only the white 8" coil and /or 7" concentric coil. I like having a 'standard' size and a smaller-than-stock size, so an 8" and 7" is fine. If I had a newer/current model that used the same series of coils, I'd still prefer an 8" white donut coil and 7" concentric coil to feel adequately outfitted.
Monte