Did a video comparison of the new games workshop Battle Mat: City Ruin vs the FAT mat. All in all, I am quite surprised that they are so comparable. Same density, thickness, print quality etc. If anything, the GW mat may have the edge (literally) because the edges are reinforced.
Still, they come in a box... <sigh>. I'll roll mine, thank you.
Enjoy! Thanks to all of you fine readers!