I've used the GL fuel bladder before, it's great. It's got lots of loops that you can strap the bag down securely on your bike with straps or bungie cords so it doesn't move around when all that liquid inside sloshes around.
That TT bladder might be cheap, but it looks kinda hard to strap down when filled up. It just has a handle.
My recommendation is to spend the extra $$$ if you can.
If you're looking for cheap, a $20 jerry can from Crappy Tire is easier to secure on a bike than that TT bag since it's solid and won't be like strapping a big pile of jell-o to your moto. It will hold its shape whether it's empty or full. It's just bulky, is the only drawback. Especially when empty, it's dead volume and can't collapse or fold up like a bladder.