My standard rig is an 18V drill/driver, and an 18V impact driver. Judging from the number of brands that offer these as a kit, I think it must be a popular combo. I also have an 18V hammer drill that I use less often, but when I need it, I need it. I think the impact driver is an absolute necessity. The hammer drill is "almost" a necessity. This is an area where I won't mix brands, due to the battery compatibility. So I'm currently locked out the Festool brand for drilling, which is too bad, because I did like my (older model) Festool cordless drill. Just not enough to do without an impact.