I had honestly not seen the "Tuff Blocks" before, but I like the concept. However, I would probably never try to use them as Haxman did as joist supports. Doing that means you have to set every Tuff Block at exactly the same elevation, which becomes incredibly tedious. I would much prefer to see them used as post supports such as in the last video you linked. Then you don't have to worry about the elevation of any of the Tuff Blocks. You just set your posts in them and then you level your deck platform on your posts using a laser level, water level, bubble level on a string, traditional level on top of a joist board, etc. That speeds up construction considerably. Now, if you simply have to build a "ground level" deck, then yes you can do it like Haxman, but you better have an engineer's level that is well calibrated because you're going to have to be very precise with the elevation of every Tuff Block or your deck will undulate a lot. The good news is, there's medication for that. TIC When it comes to Tuff Blocks vs. traditional precast concrete pier blocks, I do see some advantages to the Tuff Blocks in that they are obviously much lighter and easier to handle, and they will not absorb water the way that precast concrete will, meaning your deck structure should dry more quickly. Obviously the lumber should be pressure treated regardless, but the drier you can keep it, the longer it will last. With that said, any structure that might experience uplift from wind should be anchored to a traditional below-grade concrete pier or footing rather than an on-grade footing. Standard decks don't really meet that criteria, but if there is any sort of awning or roof structure involved, that changes things.