  Favorable propagation (FP) and channel hardening (CH) are desired properties
in massive multiple-input multiple-output (MIMO) systems. To date, these
properties have primarily been analyzed for classical \textit{statistical}
channel models, or \textit{ray-based} models with very specific angular
parameters and distributions. This paper presents a thorough mathematical
analysis of the asymptotic system behavior for ray-based channels with
\textit{arbitrary} ray distributions, and considers \textit{two} types of
antenna array structures at the cellular base station: a uniform linear array
(ULA) and a uniform planar array (UPA). In addition to FP and channel
hardening, we analyze the \textit{large system potential} (LSP) which measures
the asymptotic ratio of the expected power in the desired channel to the
expected total interference power when both the antenna and user numbers grow.
LSP is said to hold when this ratio converges to a positive constant. The
results demonstrate that while FP is guaranteed in ray-based channels, CH may
or may not occur depending on the nature of the model. Furthermore, we
demonstrate that LSP will not normally hold as the expected interference power
grows logarithmically for both ULAs and UPAs relative to the power in the
desired channel as the system size increases. Nevertheless, we identify some
fundamental and attractive properties of massive MIMO in this limiting regime.
