I guess it depends on what your set up is currently for filling and cleaning. I just have a spare coupling head with both check valves pulled from it. That lets me go into the beer out port for filling and for getting rinse water and cleaning solution in there.
This is definitely not a bad idea but I guess it depends on how you're already doing those things. A second hand spare coupling head would probably run you $10.
My concern was initially that filling through the valve would splash the beer too much. But, if it is working for you, then I have a coupler that needs a new seal. Sounds like a good candidate to pull the check valve.
Oh it works fine. The item that you posted doesn't allow you to do anything different except to control the flow.
I just have a tail piece and nut gear clamped to the end of my racking tube and line. I attach that to the top of the coupling head after starting the siphon and away we go! I invariably splashes a bit because the ID of the spear is much larger than the ID of either the siphon tube or the beer out port. But I'd rather deal with that than the PITA of reassembling the spear/valve combo on a full keg. YMMV