People, just watch this year Dubai (which was a faster outdoor hard court than any other outdoor hard court this year, though in the 90s and 80s there were SOME outdoor hard courts much faster still, let alone many indoor carpet tournaments in the 90s and 80s) :
Watch it and you can see CLEARLY that it is FASTER than the rest of outdoor hard courts they use today.
I loved it (Dubai this year). It was a surprising pleasure to see ONE tournament with a slightly fast hard court today.
Here you can see that the points in general are different. They try to win the point earlier. They are much more aggressive. Super-defence is not THAT MUCH rewarded (though it is ALWAYS an important factor on any court and condition), but great aggressive shots ARE rewarded.
Feliciano Lopez becomes a very dangerous player in these conditions, for example.
The matches tend to be closer, with just one decisive break in each set, and usually there are much more tie-breaks sets. For this reason the matches usually are more tense, there is more uncertainty, top players casualties are much easier,...
And they played with current racquet and string technology, but still you can see it was great tennis, very entertaining tennis on a fast hard court.