Last year I planted nine tomato plants out a month early and covered them up with a product called Wall O'Waters. Unfortunately, the plants ended up growing tall and leggy as they attempted reach out towards the top and the brighter sunlight. Plus since they were being protected from the wind as they grew, the plant stems were rather weak and thin. The Wall o'Waters definitely protected the plants from frost, but the tomato plants that I planted a whole month later without Wall o'Waters actually caught up and ripened at the same time as the Wall o'Water plants.

Has anyone else used these Wall o'Waters and had any success?

I have had about the same experience you note. I do use cloches (caps) to cover newly transplanted tomato seedlings on cold nights. But I never bothered to replace W'o'W's that I forgot to remove one year.

I have used the Wall O Waters for many years. Up here in Winnipeg, Canada, Zone 3 I was able to plant tomatoes outside about 3-4 weeks earlier than without the protection. They didn't grow much because of the cold weather, but were protected from frost and snow.I also planted tomatoes 3-4 weeks later and they did catch up. To prevent the plants from being weak I have a fan blowing on the seedlings periodically from the time they germinate. I still get a thin plant but they're tough and no amount of wind will knock them over. End result: I stopped using Wall O Water. More trouble than it's worth.......for me.

I use milk jugs filled with water set around plants. when the plant is shorter than the milk jug, I just drape it with cloth when a frost is coming and it keeps it nice and toasty. Wall o waters only worked for me when I would put them over an upside down tomato cage (for support for it). And they're expensive, so I just use milk jugs.