I have the m18 router. It's awesome though I am building a boat out of wood so I use it all the time. Works 100% better for what i use it for than my back friday special chinessum Metabo router that's now in my router table full time. The battery lasts several days.
I've ended up buying the m18 7 1/4" circular saw, sander, and jig saw. Really nice to not have to drag cords around for a quick cut. I still use corded sanders for major sanding, the dust collector cover on the sander sucks and is held on with electrical tape. I don't have a corded jig saw or circular saw. The circular saw requires a 5.0 battery for curved cuts, the standard batteries don't last long.