Not sure if the best, but sure a giant step in their career as they become bigger and bigger after this release. Definitely, one of the most importants albums in Thrash Metal history and Metal in general. A pleasant storm of speed!
In 1986 - hell! Today - overrated. No one really seems to give a shit about this album apart from the two obvious songs, but on the other hand you cannot really make a full album of songs with that caliber. It's good for what it is, I suppose, but it sure was a lot greater for its time. Not their best but certainly essential for any fan of metal.