This is just my straight up opinion, but certain large ship beams as well as slash beams ought to maintain their retail size.
The way freespace2 was, capital ships had a feeling about being large, and when you were in a battle you were part of something important. The size of the capship beams (corvette and up) were meant to dwarf your fighter and make you feel small. 'Let the warships do their job, you do yours' kind of a feel. I think this kind of feeling is important, and part of what sets freespace2 appart from freespace1 or, say the Descent series.
Particularly for slash beams, they make wild swipes at their target which cause damage to a large area of a target ship. With retail sized beams you have an impression of this effect as the massive stream of plasma dances along its destructive path. This sort of attack used to instill fear in me when I was in middle school, when I played the fs2 mission 'The great Hunt' for the first time.
When playing the fs2 campaign with these updated mediavps, you can really see the difference. Missions such as: 'surrender belisarius', 'feint... parry... respite...', 'High Noon', and 'Their Finest Hour' all have their most dramatic moments augmented.
The new mediavp widths are an interesting change, putting an emphasis on precision and density, but from the perspective of someone who more or less grew up to this game, they have a very unfreespace like feel to them. I advise restoring retail beam widths or at least an update which compromises by restoring the beam widths of larger vessels. I am currently experimenting with potentially new table values that do the ladder.
Lastly, respect to Hades for posting this topic and being open to opinions about his work.