Not tried that particular set, but I have used the umbrella brackets and similar stands from Impact. For the price the quality is reasonable. Do not have experience with the umbrellas in the kit.
Are you just starting out with light? if so that would be a sound $100 investment.
You actually get this same stuff with their $200 kit with the lights and reflectors. Since upgrading to AB strobes, I still use the stands, umbrellas and mounts to use my Canon Speedlights as a portable studio. Nothing fancy - just China junk but it works.
