Fabric Pots

Why Use Fabric pots?  
Well fabric pots have many advantages such as:

• Excellent drainage - more difficult to overwater,
• Larger root mass - while roots grow around and around in a plastic or ceramic pot, the air at the edge of the fabric causes a root tip to dry out, and die off. Just like pruning the top of the plants, the roots will branch into many smaller roots because of "air-pruning". Therefore, the mass is larger and made of more smaller, more effective roots.
• Generally speaking, the bigger the roots, the bigger the fruits,
• Higher oxygenation to the roots, 
• Encourages aerobic bacteria/microbes,
• Evaporation may reduce root zone temperatures (it's a plus/negative sort of thing as the pot will dry out more) Its definitely worth running a side by side comparison,
• and they're easy to store.

The only negative is the same amount of media in a plastic pot will usually hold more water. So having more media by increasing the size of the pot may be best for fabric pot growers.