I'm so far impressed using a slightly modified 5-1-1 in fabric Smart Pots with ground contact.

I used somewhat smaller fines in this mix (only 1/4" or smaller instead of 3/8"), but otherwise it's "regular" 5-1-1. I had concerns about the wicking and evaporation of the smart pots causing me to need a LOT of watering, but I've found I can get by nearly a week without watering, but that may change as the pots fill with more roots.

Here's the WOW factor for me -

June 25, I transplanted some Scarlet Oak seedlings that were in 3" square, 4" deep root pruning cells (Rootmaker 18-cell trays) into the 1 Gallon smart pots.

Yesterday, I moved one and noticed that it had some resistance - in three weeks - a dozen or so roots had penetrated the fabric into the soil below. In THREE WEEKS! An OAK seedling!

I don't know if it's the vigor of the plant, or the breathability of the pot and 5-1-1 mix, but I'm impressed.