The Chief can be directly mounted to the ceiling and twisted by the attaching screws in curved slots. Installation is far eaier on any mount with a ceiling flance (female 1 1/2 NT threaded socket) and a piece of threaded at each end 1 1/2 inch threaded pipe. They come as short as 2 inches, all threads.
Each mount really has only two adjustments. Left right bank and up and down tilt. That's it. Left right to put the lens perfectly parallel horizontally is accomplished normally by twisting around the pole. Top bottom parrallel is accomplished by the up down tilt. Really it makes little difference in how easy it is to do because you do it once and one vs the other may save you two minutes. I prefer the Chief RPMA but the RPA works just as well. I wouldn't stress too much about which one is best. I think the Chiefs are bettter than the Peerless, more stable over time. None come with the ceiling attaching bolts. This., the size and strength of the ceiling fastening, is nothing the mount companies want to face liability for and they pass off what is necessary to the installer with the necessary legal disclaimers.