Hi Reed, I had thought about gold hog mat, but due to it's solid riffle wall design it will not accept the curve required to be installed without deforming the riffles. I first started with miners moss and drop riffles cut from a piece of pvc pipe but it was difficult to lock down the riffles tight to the miners moss without a lot of force which could lead to breakage. Tried a lot of different things before trying this mat. Since the fingers create the drop riffle walls which are approx. 1/4 deep and 1/4 wide, the natural effect is that migration into the fingers occurs and helps protect it from scouring. Next time your at Lowes pick up a piece to try, comes as a 17X28 door mat. I run slow at about 1fps. Whenever I do any major testing, I will run 2-3 gallons of material through to build up material in the riffles, then 2-3 gallons of salted material, then another 2-3 gallons of unsalted material. This gives me the ability to capture the material separately for panning it out to look for losses whether they are direct capture losses or migration losses. I simply do not see migration losses more than a fraction of 1%. I think you will be impressed with this mat's ability.