personally i think that when your model is ENOUGH detailed what improoves the look of the models are not more details but textures
now, does somebody know how long it takes to make high quality textures? lemme tell you that: to redo all the fs2 textures at higher quality it will take at least an year of hard job for a TEAM of texturers
something that may be done, instead is to resize actual textures to higher resolutions:
most progs draw the additional pixels coherently with the originals, so no details will be added, but they will probably look sharper and better
it may be worth a try, maybe someone should keep a model and try to resize its textures to 512x512, and check the result
i have only a little doubt....
when you resize a texture you have to redo all the uvmaps? i don't think so, but...