It looks nice to me 
- it might look a little 'flat' compared to other parts in the picture, but I think thats because of lighting rather than texture resolution. Excellector's texture has a "baked-in" shadow on its top that is fighting against Oblivion's real time shadows that are underneath. That lowers contrast instead of making it 'pop'.
Also, Oblivion is using fancy lighting tricks like bump mapping to make parts (like the rock in the lower right corner) look like they have tons of 'peaks and valleys'. Does Oblivion's importer tool let you import bump maps for your textures? I'll bet Verdite or AirFlamesRed know an easy way to generate a bump map for a texture.
- it might look a little 'flat' compared to other parts in the picture, but I think thats because of lighting rather than texture resolution. Excellector's texture has a "baked-in" shadow on its top that is fighting against Oblivion's real time shadows that are underneath. That lowers contrast instead of making it 'pop'. Also, Oblivion is using fancy lighting tricks like bump mapping to make parts (like the rock in the lower right corner) look like they have tons of 'peaks and valleys'. Does Oblivion's importer tool let you import bump maps for your textures? I'll bet Verdite or AirFlamesRed know an easy way to generate a bump map for a texture.