We had been using Pfizer’s Revolution before but after outdoor walks our dog would eventually come back with ticks which could take 2-3 days to die off. We switched to K9 Advantix II because not only it kills but more importantly repels ticks and fleas. The two products have many differences and a veterinarian should be the best person to help choosing.
Disclaimer: Always follow the instructions that come with the product there different versions, dog weights, etc. And remember, NEVER use K9 Advantix II in cats.