The Quasar is way more massive and less manoeuvrable than an MC30 despite the MC30 being longer.
Whatever size a ship ends up with probably is a factor of how massive they are and how manoeuvrable they should feel when used in the game. The Quasar probably are in the lower end of the medium spectrum while the Gladiator are in the higher end as they both probably are equal in mass, roughly speaking. The Gladiator though act very differently and as such end up as a small rather than a medium. The MC30 makes for a very good (large) small ship based on its features... it is very long but sleek and still relatively small in comparison with both the Quasar and Gladiator in pure mass or volume.
Edited by jorgen_cab