Hi I started a company about 6 months ago (not gonna name it here because I'm not a sponsor). We got feed back from a moving company on which ones are the best and they basically said to stay away from any of the cheap brands as their build quality is not going to be nearly as consistent and are more likely to end up losing their seal on the glass. When I go into the warehouse this morning I'll be sure to check what brand we are using as I don't remember off the top of my head, but we have used it for a 300 gallon tank we are taking to the orlando reefapalooza show (if it stays open)
Tips: make sure the glass is super clean, have as many people as you can (you don't necessarily need suctions cups for everyone as they are best when lifting and setting the tank down but the more the better). Most of the time the suction cups will slip a little before actually letting go if that happens go to the ground as fast as you can.
What we generally do is we use the suction cups to lift a tank and set it down on a set of dollies, we roll the tank where it needs to go and then we use the suction cups again to lift it to where it needs to go. This way reduces the risks of drops.