It is interesting. The techniques for creating dies has changed a lot over the millennia -- all the way from hand-engraving (then) to laser-engraving (now).
I'm biased because I specialize in 18th/19th century US stuff, but I think those were the best-looking (overall - not necessarily just the designs themselves).
Dies were made by starting with an actual-sized engraved positive which was used to make the working dies (negatives), which were then polished to make the coins (positives). You get cool errors and varieties from slight differences in dies (that crack and break over time) and things like hand-punched dates (why re-engrave a whole new master when you can just take the main design with a blank date, create a die, and smack in the "1895" with a hammer? :)
I think the modern modern laser-engraved stuff has lost something...the coins of today are almost "too good" - they're kinda flat-looking & soft. shrug
It had been way better earlier, both on Roman and Greek coinage. Some of the Greek coins would put anything modern to shame. For some reason the quality of the coinage at the end of the roman empire (what we'd call the byzantine empire, even though they'd have just called themselves romans) took a major turn for the worse in terms of artistic quality.
The declining quality probably correlated with the military setbacks the Byzantines were dealt by the Arabs and later by the Turks. Heraclius finally defeated the Sassanid Persians in 622 but lost much of the Holy Land to the Arabs by 640. [1,2] The crushing defeat of the Byzantines at Manzikert in 1071 [3] led to a series of events that resulted in the Crusades.
