Mine grew better than the ones done the traditional way. They were a little later to germinate, but never went through any transplant shock and took off growing immediately when planted in the ground. I was able to put them out in the ground earlier since they grew up being subjected to cool temps from the beginning. Also no damping off.
Here are some of the milk jugs planted the middle of Jan (temps into the middle teens), but photo is was taken in March when they were filled with tiny seedlings. Second photo is first part of May. I transplanted them into 16oz. plastic cups, they got too big and over crowed in the milk jugs. These were planted out right after this photo was taken. I put the top half of the jug over each plant at night until danger of frost was over. By then they were huge and the jugs wouldn't fit over them anymore. They outgrew and out produced all the plants others had put in as blooming/large plants. I also planted 3 plants I got from our local farmers market. The winter sown plants out performed against those also.
I did over 200 tomato plants and gave many away.
Collards. I was surprised at how easy these transplanted to one of the raised beds, I also didn't know that collards could get a big as these did.
