I'm talking about the aesthetic and technical merits of the shapes and forms.
Personally I feel like they fighter designs are just not as logically laid out. For instance, the "Falling Leaf" has a huge amount of unnecessary-looking surface area, which makes it easy to hit. The cockpit looks odd and protrusive, and not very well implemented, aesthetically or logically. Indeed I feel that making the red section in the back, or burying the cockpit completely, would be a more meritorious choice.
The modeling, texturing, and lighting, is quite good though. The model looks very well made. 
Well, you'd be surprised as to how much you've hit the nail on the head.
The 'Fluttering Petal', the canon fighter starlord mentioned, served as a major inspiration point for the Leaf. What I essentially did was rip off its turret (the 'Petal' is a heavy fighter, and thus has a turret), and move its wings from the rear half of the fighter to the front. While the 'Petal's' wings were rear-swept, I made the 'Leaf's' wings forward-swept, to keep the smooth lines of the hull.
The 'Petal' had no extruded cockpit - it was pretty much flush with the hull. But I grabbed the cockpit of the 'Warspite', a joint Terran-Kess'Rith design and threw it on the 'Leaf', because it'd look 'old' (kinda WWII-like). Don't forget that the campaign we're currently working on dates almost two centuries before the 'main' Renegade Legion storyline. If we ever reach the point of making a 'modern' RenLeg campaign, I'd like the ships we make to 'feel' more streamlined and 'new' than these old crates.
TL;DR: My designs are
purposefully clumsy (while staying as true to the canon FASA desings as possible), in order to accentuate the 'old-ness' of the time period in anticipation of a more 'modern' campaign.