It was easy to fill, and I filled mine with sand. Fill tubes fold under and into the pockets on the bottom the bags. The location of the fill tube pockets and weight of the sand seem to prevent leakage.
One of the bags did come with a tear in the fill tube, but I didn't have any problem filling the bag. I gave 4 for the overall rating because of the tear.
This review was written in the old system and had content requirements that are different than reviews written today.