Big natural tits > small natural tits > big fake tits > no tits >>>>> small&flabby tits
Of course the big fake tits are easily identified from far away, but there are more fake tits around than you realise. Some look very much like medium natural tits if done correctly, and only reveal themselves when you touch them or when the women lies on her back and the tits don't move to the side but still stand up. They feel different, not necessarily worse though.
As for asses, that's the age-old question of what is more important.. titties or ass? Or more precisely, are you willing to accept a fat ass when it comes with big tits, or are you willing to accept no tits when they come with a nice ass?
The opinions really differ on the matter.