I asked that question to X10Pro myself.
Wondered if the software was STABLE and
FUNCTIONAL since they had been out a
while. Followed advice and purchased.
It is now months later and the macros I
want to use still WILL NOT WORK. If you
have faith, as I still at this time do, go
for it.
If you want to use X10 cameras and iWitness
with SM, then you will not find another
product to compare to for the price. But
you will be waiting for bug fixes and
possibly some additional hardware purchases
(RF reception to unload tasks from the
CM15A).
My experience so far, and still waiting.