Oh, there's no doubt about how awesome it looks. But here's the problem. At the moment, I think those cockpits use textures in the 512^2 to 1024^2 category, while accounting for several hundreds of LOD0 polygons. Actually, let me pull up the correct stats.
For the Uriel gunship (wraith.pof), for example, the cockpit has 2289 polygons, and it uses 4 1024^2 and 1 512^2 diffuse texture. All of these have glow, and some even have normal maps. Meaning we are talking about around 10 MB of video memory for these cockpits alone.
Now, the problem is that these cockpits are rendered whenever LOD0 of that ship is visible. Due to the way the FSO engine is set up, this incurs a disproportionally high cost in terms of ressources.
Now, if Steve-O had done the smart thing and used the ships.tbl option I linked to above, that cockpit model would only have to be rendered once, for the player. As it is, they need to be rendered or at least processed for ships that, in most cases, won't ever be close enough for you to see those cockpits.