Anyone use a borescope for cylinder inspection?

I got a Rigid brand for Christmas and the picture is really nice however the camera is too large to get into my spark plug hole. I would like to be able to view the ridge and valves also. Checking on Amazon and they have dual camera and articulating camera. Looks promising. It's not going to be getting a lot of use so I don't want to spend a lot of money on it. I don't mind using my smartphone for the interface. Does anyone have any experience with these? Thanks.