I tried the Cashel belly guard last summer and actually liked the design a lot. Unfortunately my big shouldered, short backed Fjord seems to be in between their sizes, so it was either too tight in one spot or too loose in another. It tended to come loose/out of position if he rolled vigorously. I think it would have worked if it had a few more straps in strategic places. I did like that it protects the chest and the area between the front legs. He has sweet itch and often that’s where the gnats started biting first.
It is nice, light weight, so not hot in the summer. It’s also very easy to just hose off to wash and hang over the fence to dry quickly.
I have not tried the Belly Dickie, but think those extra straps would help keep it in place well (might be just what I might need). I have to say it’s pricey though compared to the Cashel model which is quite reasonable on the price.