Luckily press previews generally use the original voices, as was the case here. It was the original version.
I like them but I didn't grow up with them. So I don't really count myself among the big Star Wars fans, even though I read a few books, played a whole lot of SW games and of course watched all of the movies. There's obviously a difference between people like me - who enjoy the universe but don't think the OT is the be-all end- all for the franchise - and the people who grew up with them and hold the OT in a very special place in their heart.
Talked with quite a few and general chatter in the Foyer after the movie. Comparisons with 7 were running rampant. Obviously not a mathematically correct statistic
Entirely possible it's actually 1/4 to 3/4 or other way around.