1/8" vs 1/4" closed cell pads

I just received a new 1/8" foam pad to use under my Thermarest NeoAir X lite, it weighs in at 4 oz versus 8.4 oz for my 1/4" pad.
It is mainly used to protect the expensive NeoAir from Sharp things on the ground, I like not needing to carry the extra 4 oz, but I am worried that it might be too thin. Only time will tell. 

The 1/8" pad is on top, 1/4" below, they are both Sold by Lawson Equipment

The newer 1/8" has cool straps and logo