  We extend the study of the nature of the Hagedorn transition in NCOS systems
in various dimensions. The canonical analysis results in a microscopic
ionization picture of a bound state system in which the Hagedorn transition is
postponed till irrelevancy. A microcanonical analysis leads to a limiting
Hagedorn behaviour dominated by highly excited, long open strings. The study of
the full phase diagram of the NCOS system using the AdS/CFT correspondence
suggests that the microscopic ionization picture is the correct one. We discuss
some refinements of the ionization mechanism for $d>2$ NCOS systems, including
the formation of a temperature-dependent barrier for the process. Some possible
consequences of this behaviour, including a potential puzzle for $d=5$, are
discussed. Phase diagrams of a regularized form of NCOS systems are introduced
and do accomodate a phase of long open strings which disappears in the strict
NCOS limit.
