I have never seen this movie theatrical or on other media than these 2 DVD's so my comments is only based on my impression watching these. The Italian Shock has the Italian opening credits which is in a horrible quality with lot of print damage, but when the credits is over the amounts of white speckles is reduced, still some but "acceptable". The Blue Underground has English opening credits and only few speckles trough the movie. While the Blue Underground has a higher resolution and is anamorphic it's more soft and poorly detailed than the old Italian Shock release, and it also seems that the brightness is turned up a bit so nighttime scenes is turned to daytime, on the other hand the Italian Shock looks a bit to dark. The green tint on the Blue Underground captures isn't quite as noticeable viewing on a TV.

A lot of DVD reviews has mentioned that the Italian Shock is cut, I have simultaneously viewed the first hour of both releases and found 138 missing frames (5-6 seconds) in 7 scenes compared to the Blue Underground, why this I have no idea because the gore effect is the same, it's only extented clips, for example 2 seconds where we see Murolo's face when he find his wife dead. A "funny" thing is that the scene where Mickey has his brain blown out is longer on the Blue Underground DVD but is missing 1 frame compared to the Italian Shock (see last capture(s)).

With the longer running time, the lower amount of print damage, the anamorphic picture and the soon re-release with a low price I marginal recommend the Blue Underground release, but if you own the Italian Shock I don't see much in upgrading.