.. ignore Emmanuel's no doubt sage advice regarding the sizes of both models and textures...

Oh, I agree, for better rendering it is often good to use more elaborate models. However, there is not always a direct relation between size and quality, some models are not huge because of beautiful small details, but just because they are a mess of badly put together surfaces. But of course, there is nothing wrong in using large file models or large textures if your computer can cope. ok