I have a Karcher K1700. I haven't used a foam cannon with it but it works well for me and isn't obnoxiously loud. Also, I believe it's one of the few big box store/homeowner grade machines that got a favorable review in Obsessed Garage's tests.
Yes they are good little machines…”eyes wide open” it does have a “planned life expectancy “ I’ve had the karcher…green works…active and I finally bit the built and went with the kranzel T1622TS What a beast !
Very nice tool and with planed maintenance I’m betting on this being the last one I’ll need