The last time I visited this place it turned out that the name was changed to the owner's name but I forgot his name ;-)
Not really important cause it's still the same old dark, smokey shithole you're looking for after hours.
The atmosphere really depends on what night you come in, could be lost drunk students, or coke sniffing criminals having a party.
Rule of thumb is that if Ajax (or the dutch team during a cup) won an important match it's crowded, cheerful and the night will last very long.
Oh, and there's a four square metre dancefloor in case you brought your lover for a romantic night out..