I think it's pretty good. It seems like a LOT more work was put into the design and the sets than the cobbled together Ancient warships from Atlantis, which were frankly boring designs. It does feel as if they're on a spaceship. It may also be working precisely because this Ancient ship, while advanced, is old enough so that it's only a little bit ahead of human technology (Stargate humans, with their own alien-derived spaceships). So, they're not trying to think up something that should be 10,000 years more sophisticated than present day human science.
I actually get a rather The Black Hole vibe from the ship, and IMHO that is a very good model to emulate! The megaship in The Black Hole really created a sense of vast, creepy isolation in the void that few sci-fi movies or tv shows have ever equaled. With the apparently increased CGI effects budget, I hope they can show some massive spaces inside the ship and outside it, and have some lonely EVA scenes. In my view, the show would be smart to go with the angle of portraying the humans on the ship as tiny and lost inside a hostile void; but rather than take the BSG route of neurotically focusing on smelly sweaty people crammed together in tin cans, go the opposite route. I want to see some serious agoraphobia and rapture of the deep.