I always thought which of the two were easier to transport? Of course their's manufacturing and cost of course. But, there's also the cost of transporting. Which costs more to transport. In money and fuel. Whether it be a weapons transport transporting these weapons all the way to a whatever ship was meant to carry them. In this scenario, i'm considering weight, and even compactness (how much more of what can you carry in a smaller space aside from power, of course, not the only aspect).
Traditional kinetic weaponry rely on the usage of a chemical propellant to accelerate and transfer energy to a bullet or slug, which then transfer what energy it has to the target (or otherwise punch right through it). Therefore, traditional kinetic weapons "consume" mass from the propellant, the slug, and for rapid fire weaponry, the shell. The shell or case is used to conveniently hold the propellant and bullet together, as well as serve as a heat sink for any wasted energy from the propellant's discharge.
Railguns and coilguns use electromagnetic force to propel bullets or slugs, thereby reducing the amount of mass consumed to just the bullet. However, depending on the technology used to generate and store the electrical energy, the net amount of mass of these weapons may be greater than the traditional counterparts.
Armor against traditional kinetic weaponry (including railguns and coilguns) seeks to either absorb all of the kinetic energy of the slug without penetration, or to divert/reflect the slug away. Even if there was a hypothetical armor that could absorb all of the kinetic energy of any slug that hits is, sustained fire at a single point in the armor will eventually heat it up, perhaps even to a melting/softening point at which the armor will fail.
Energy weapons, namely lasers, beams, and electromagnetic wave weaponry (such as a Microwave gun or a X-ray gun) seek to destroy material by raising its internal temperature or otherwise alter the molecular bonds so that the material's molecules will unravel themselves.
EMW weaponry (including lasers) all travel at the speed of light, so their precision is phenomenal and is not affected by gravitational forces for sub-AU distances (like all types of kinetic energy weapons are).
Beam weaponry (including lightning-type weaponry) for the most part behave exactly the same as kinetic energy weaponry, but have the capability of being a continuous stream. Additionally, beam weaponry can have the same effect as laser and X-ray weaponry on the temperature and molecular stability of material.
Just like traditional kinetic weaponry, Beam weaponry requires the "consumption" of mass in order to create the bolts. Lightning-type weaponry require a conduit of some sort in order to transfer the electricity from weapon to target, and this conduit is usually a stream of conductive particles (a.k.a. a beam). Lastly, as with the Laser and EMW weaponry, depending on the technology level of power creation and storage, Beam weaponry can have much more mass than laser and traditional kinetic weaponry combined.
However, if the consumed mass of Beam weaponry is fissile, like radioactive materials such as plutonium and uranium, then the energy requirements of beam weaponry would be mitigated to only the amount of energy needed to start the chemical reaction of the beam material. Read: controlled nuclear blasts in the form of a beam.
TL;DR:
Chemically Propelled Kinetic:
Pro's: Low tech requirements; Light-weight guns; Resistant to atmospherics
Con's: Ammunition limited to amount of materials for bullets, shells, and propellant; Fired munitions go on forever, potentially hazardous for non-combatants; Fired munitions are affected by gravity; Consumes mass
Magnetically Propelled Kinetic:
Pro's: Higher precision and range than Chem propelled; Resistant to atmospherics
Con's: High tech/energy demands; Fired munitions go on forever; Munitions affected by gravity; Consumes mass
Electromagnetic Wave Weaponry:
Pro's: Highest precision; Highest speed; Continuous operation; Unaffected by gravity; Can be "harmless" after a specific range out of focus; Doesn't consume mass
Con's: Potentially slow in transferring necessary energy to destroy target; High tech/energy demands; Vulnerable to atmospherics/ablative armor
Particle/Beam Weaponry:
Pro's: Good precision; Semi-continuous operation; Fast in melting or otherwise destabilizing material on contact; Munitions can destabilize after a specific range
Con's: High tech/energy demands; Speed limited to type of particle used; Munitions affected by gravity; Vulnerable to atmospherics/ablative armor; Consumes mass
Disclaimer: I disclaim any and all information here from being 100% accurate, partially because energy weaponry is not widely known in their operation.
