I'm planning on setting up a small phone system (~5 phones) using
Asterisk for an organization and I'd like to hear what others who have
used Asterisk think of it.  What do you like about Asterisk and what
issues have you had?  Would you recommend using Asterisk over a
commercial PBX system and why?

If the system is implemented, we would start off using the Digium cards
to interface with two analog phone lines, so I'm curious to see if
anyone has any experience with Asterisk and those cards and any issues
along those lines.

I've put together a proposal for this organization and am just lacking
any previous experience, so responses would be used to put into the
proposal. 

Feel free to respond on or off list whichever you're most comfortable with.

Thanks
Jeff Lehman