Actually, it doesn't look to have thousands of polygons. At top I'd say 1000, it's only the normal smoothing that might confuse you. If I had to guess the whole model, except that small boxed chain thingie, has around 400 polys (plus around 300 for the chain thing), though it's hard to determine that black thing where that chain thing is on.
But yeah Doc's right about that much of that model could be equal detailed with texture and bumps. That 'spiral' thing just before the gun is one such thing.
My guess would be 1000 polys. One limit should be to keep the poly count for one turret below 1000. I'm not making much turrets (in fact I stopped) as I do not have time as I explained before. Working on my own projects except for weekend where I usually just sleep, play or watch something.
But seeing that so many people already model on these things I am not needed anyway. Now if only these people would make player models
PS. I love Morphed turret design. It's delicious!
PPS. One tip to you Doc. I see that you use some of the same texture that to your own stuff (that spaceship for your map comes in mind). I'd rather see the turrets more to the gray metal direction like Morphed has done. I'm not sure that green thing really suits that turret model.
Also, smooth the edges of the chain guns to give it smoother feel. It looks off as it is now. If you take a look at Morphed design you'll see it, it looks so good I could eat it.
