Sir: I do prefer compression couplings for EMT conduit. My principal reason is that they do a good job of maintaining the structural integrity of the system. I, like you, never depend on conduit alone as a ground return path. I always use an equipment grounding conductor. I will accept set screw fittings if necessary, but have one major requirement for their use. If you use them always have the set screws on the top of the conduit. Most times they are overtightened and this will deform the conduit slightly. If this happens on the sides or especially the bottom, it creates a sharp ridge in the conduit. When the wire is pulled in, especially large wire, the insulation can get skinned off on that edge. As long as the contractor understands this concern, there is usually no problem. Hope this is helpful. Phillip in Kentucky, doing consulting engineering for 35 years.