If I didn't know better, I woulda thought that the underside turrets were wheels. 
Rolling,rolling...
http://www.clayh.net/fs2/rawhide.htmThe large panels do look better, but I would add back some of the color variation, wear and tear etc. I looks flat atm. Very nice model.
On the flatness I agree, I'll play around with adding a third layer with some colour variation in the end stages. (nitpick stage!)
I altered your wip shot 'cause I wondered what it would look like with the lighter center. Decided to share.
It was a bit dark on that area on the render, showing off a side shot with possible glow spots, but thanks for the idea.
Underside turrets look a bit too big (so too easy to shoot/damage), but it could just be me. The curvy barrels also don't make sense to me.
Otherwise, a very good looking model.
I tend to agree on the size of it so I reduzed the general size, but the curvy turret stays! ( I can draw up a diagram on how it could theoretically function c:)
The curvy barrels also don't make sense to me.
SENSE ? IN MAH FREESPACE ?
DO NOT WANT.
I second this!

Thanks for feedback.
You're very welcome.
Did a lot of texture redesign...
No kidding! It's looking badass. Your texture work on the cabin and tech details is astonishing, it actually reminds me of Geiger's artwork. The armour plating looks a bit plain by comparison (though I do like the chunky new plates
). All in all, it's impressive, and with normal and shine maps, it's going to [sunglasses] shine [\sunglasses].
Couldn't resist. Please don't hurt me!
I was a huge fan of Gigers work when younger but now, a bit less but still enjoy his work. c: I dread when starting with normal mapping , I'm not very good at it

Turret redesign, added more swirls to the curves.

(turret textures need more work) , worked on the underside mostly and fixing errors in the mechanical parts of ship, aaand now starts the nitpicking stage.
