as a veteran of combat flight sim 2, a game that makes a serious attempt to have a realistic atmospheric flight engine, i know a thing or too about realistic physics. there even worse when you have a ground to run into (or usually the case in cfs2, the paciffic), add the difficulty of carrier landings and you got an asshole with mad skills. i dont mean to diss i-war, cause i never played it, ive been looking for a copy, but no luck.
i never sugested using newtonian physics in freespace. ship stablizers keep the ship under control so the pilot can focus on combat (which kinda fits the plot). should the stableizers fail, you have to counteract every action you make, essentially newtonian physics minus the theory of relativity, though i perfer the term zero friction physics.
tachyon nebulas consist of layers of transpatent planes, that are bland looking, tiled textures. freespace textures, with the dibrits sprites and models, poofs that swirl and rotate into eachother. the effect makes them look like they have volume. for freespace being a year or so older than tachyon, it clearly has the better engine and definetley a better plot.