I tried smart pots one a 20 gal other a 10 gallon for overwintering both plants were transplanted last fall into the SP"s and they did much better then the plant that i did not put into a smart pot.. Aero pots are quite expensive i have also thought about trying them but have not yet..
I have not seen any "Roots" squeeze through the felt yet but its only been 5 months they have been transplanted into the sp.
I have a few more sp's i have not used yet 7,10 &15's gal. and i think if i continue to use them i will stick with the 15 gal. the 20 gal is quite heavy (75 lbs) when i did the transplant of moist soil + plant.