It's not the cheapest but it's the only one that claims to handle bead leaks. Alloy rims tend to have that problem. On one of my bikes I could spray soapy water around the rim and watch the bubbles form. Being lazy I decided to give it a try last spring. It worked and the pressure held all summer.
I also have a studded tire on an alloy rim that was leaking. I'd had it back to the tire shop but it still would bleed down. I used it when I mounted the studs last month and so far it's holding at 36 psi.
I didn't notice any balance problems either on the bike or the car. There is an injector where you can measure a specific amount or the the pouches come with a tube so you can wing it. It also includes a core remover and a valve stem cap so you can tell which tire it's in. It seems to clean up better than Slime if you spill any.