I have two of these. They hold a lot of water and work well for me. They are definately not the quality you will find with Fly High or Launch Pad. I just didnt want to shell out the cash for the more expensive ones. I sometimes wish I would have bought nicer sacs because at time I get worried someone is gonna toss there board on the sac and puncture it, but it hasnt happened yet. Id give them a 6 out of 10.
I bought them, credit card went through and everything, then yesterday Masterline called and said they were out and tried to up-sell me to a larger sac. Said it would be 2 months before they got anymore in. Bummer.