Growing up north, I wasnt a fan of grow bags for my peppers. I use them for other plants, but the bags don't get as hot as the buckets....up north we take all the heat we can get for our peppers!
I love my double cups and double buckets because it means the plants can go through some very hot and dry weather without needing to be watered. They're easy to move around and they last a lot longer than the fabric which degrades in 2-4 seasons.