I state my conclusions first that Indian in 320 to 200 bc was more advanced than china but I do not think Maurya empire was larger, wealthier or even more powerful than han empire.
Mauryas did not have more than 40-50 million people and had less developed bureacracy than hans as well as technologically hans were using many machines which was not even used anywhere.
Though I think infantry of Maurya empire was quite sophisticated but it lacked a great cavalry .
Hans were certainly larger and more technically advanced and given similar per capita estimates provided by all economic historians , I think Hans produced more wealth in 50 bc to 50 ad than india in 300-200 bc.
however the idea that Mauryas had not used coins is downright ridiculous.
when Mauryas appeared on scene, India had seen metallic currencies for some three centuries already and we get mauryan coins from all parts of india except Tamil region which was not within the pale of the empire.
Also, Mauryan road system was greatest of their time ( i mean 300- 200 bc ) as we find a 2,000 km long road with milestones at every 3 kms and resthouses and wells along with men in charge of these things at every 5 km.
all this is verified by greek sources so reliability is well established.
also, their logistics was great as they transported a pillar on a 42 wheeled cart pulled by 2,000 men and the cart being 80 feet long with pillar's weight more than 60 tons to a distance of 700 miles.
and be rest assured what mauryas achieved in arts was never achieved by any asian empire till that time and I have yet to see Han era sculpture that can resemble the maurya age sculptures and pillars.
this is image of a yakshi ( indian mythological nymphs) of maurya times.
this is national emblem of India and do not think it is photoshopped, the polish is what has amazed even europeans.
this was built and installed in my city during Ashokan time.