I think the real question to answer here is the role that the weapon should fill. For example, an ion beam is useful on any ship that needs to keep enemy shields up at a distance (Allowing support Falcons to do their jobs very well), a graviton beam is a safe option for a spare medium energy slot that improves performance in relatively even fights (which fits nicely on many Paragon builds, and helps flux-hungry Sunders perform better in a support role), a phase lance works best on ships that are maneuverable enough to make use of a close-range strike weapon, but not enough to make good use of an antimatter blaster (making it a good fit for the Eagle), and a heavy blaster lets a ship with lots of spare flux and no heavy weapons deal heavy damage (which suits the Aurora).
I don't see many situations where "I want to shoot down missiles with my medium energy slot" comes up. IR autolance is a flexible weapon that can shoot down fighters while performing other useful jobs, and shields obsolete PD on most ships with a medium energy slot. If it could serve as an alpha strike weapon, it would need to differentiate itself from the phase lance and the antimatter blaster, and "alpha strike weapon that's also point defense" seems like a very strange niche. Is it meant to be a high-tech counterpart to the Devastator?