Can I answer with an 8X? It's funny I stumbled across this, because as soon as the DP for 8.1 came out I switched to 3 columns with a photo skinned behind them. I think I was dying to be able to do it, because originally with GDR3 I wasn't allowed to due to screen size.
Funny enough, I have gone back to the 2 row, solid color "classic wp8" look and I find I actually really missed the simplicity! The double wide tiles are a thing of beauty, and the information at a glance is much easier to make out.
I think I'll stick with the 2 row for the foreseeable future, and I'm really surprised that I feel that way lol.