One of the most consistently-observed characteristics of UFO flight is a ubiquitous pattern in which they tilt to perform all maneuvers. Specifically, they sit level to hover, tilt forward to move forward, tilt backward to stop, bank to turn, and descend by "falling-leaf" or "silver-dollar-wobble" motions. Detailed analysis by Hill shows that such motion is inconsistent with aerodynamic requirements, but totally consistent with some form of repulsive force-field propulsion. Not satisfied with paper analyses alone, Hill arranged to have various forms of jet-supported and rotor-supported circular flying platforms built and tested. Hill himself acted as test pilot in early, originally-classified, versions, and found the above motions the most economical for control purposes. Pictures of these platforms are included in the text.
In an effort to examine the force-field propulsion hypothesis yet further, Hill analyzed a number of cases involving near-field interactions with an apparent craft in which some form of force was in evidence. These include examples in which a person or vehicle was affected, tree branches were parted or broken, roof tiles were dislodged, objects were deflected, and ground or water were disturbed. Under close analysis the subtleties of these interactions combine to point unequivocally to a repulsive force field surrounding the craft, while discriminating against propulsion mechanisms involving jet action, pure electric or magnetic effects, or the emission of energetic particles or radiation (although the latter may accompany the propulsive mechanism as a secondary effect). Further detailed investigation indicates that the particular form of force field propulsion that satisfies observational constraints is what Hill labels a directed acceleration field; that is, a field that is, in general, gravitational-like in nature, and, in particular, gravity-canceling. Such a field acts on all masses in its sphere of influence as does a gravitational field. Corollary to this conclusion is that observed accelerations ~100 g's relative to the environment could be sustained without on-board high-g forces.
Apart from that I haven't seen a scientific review of Hill's book. It'd take me a while to write up a detailed review, but to attempt a quick one to answer your question:
Basically Hill's approach is to assemble the data from some major UFO cases and then analyze it scientifically from a physics perspective with an aim towards identifying a possible mechanism for observed properties of UFO propulsion. He first considers things such as observed weight, mass, density, etc., which leads him to the conclusion that UFOs have mass in a range heavier than a jet aircraft; speed/acceleration performance, which he concludes can be explained in terms of known physics of controlled high accelerations; illumination color, which he sees as evidence of an ionized plasma sheath; and radiation and temperature, which leads him to conclude that UFOs radiate between 25 electron volts and 3 million electron volts, into the lower end of the gamma ray spectrum (relating to the ionized sheath). Then he starts considering possible propulsion mechanisms for UFOs' observed near-earth performance (to be distinguished from any interstellar performance, since these may involve different mechanisms), and after ruling out a number of possiblities (particle ejection, pressure, rocketry, electric fields, magnetic fields, etc.) by process of elimination he argues for force field propulsion as the likely mechanism. After considering a number of different types of possible force fields he concludes the one involved in UFO propulsion is similar to gravity but acts in an opposite manner. Once he advances this hypothesis he develops it in technical detail and relates it to other observed data such as UFO humming, dynamics, subsonic and supersonic operation, aerodynamic heating, etc. Towards the end he addresses objections based on relativity theory. The gist of his argument is that observed UFO performance does not violate the known laws of physics, but, however, does exceed human technological achievement as it stood at the time Dr. Hill completed his manuscript in 1975, in his stated opinion. He does not get much into discussion of classified aircraft programs such as those emphasized by authors like Renato Vesco and David Hatcher Childress in Man-Made Ufos 1944-1994: 50 Years of Suppression, which is an area I still have unanswered questions about.
I agree on the difficulty of sorting out disinformation. I have my own way of approaching it which is probably different than others. For one thing I look at the background of the person making the claim and possible political agendas, and when someone has a counterintelligence background like Doty does that immediately raises a red flag. I also look for known propaganda techniques, such as incomplete presentation of data, one-factor analysis which excludes consideration of other relevant variables, attribution of statements to anonymous unverifiable sources, etc. Another thing I look for is consistency between known facts and claims where the facts are in question. With respect to this I've found looking through old news accounts and declassified documents helpful because it helps establish a timeline of when reports of phenomena occurred and how the government and media responded to these reports, which helps establish at least some facts in the case. It's complicated, as I know you know! :)
Hope that helps save you at least a little reading time! Have a good night and enjoy your reading! :)