[Cialug] cygwin implications and concerns?

[Nathan C. Smith]

Is anyone familiar with any security or stability implications to running Cygwin on Windows 7?
Does the Windows 7 networking level control access to Cygwin?
Do the Cygwin processes create a drain on the machine?
Is the Cygwin subsystem always active, or only when used?

It has been a long time since I installed Cygwin and I'd like to hear from folks with experience or expertise.

Thanks.