I'm assuming you're speaking from hands on experience here?
Last time I fired up my copy of ePSXe, the games I played (Front Mission 3, Grandia, Xenogears, Rival Schools, etc.) had no such distortion on the polygon models. In fact, the games looked absolutely fantastic with the higher resolution and smoothed/cleaned up textures.
But then again, I guess it's all about which video pack you get.