I've been lurking here for months, mostly reading your initial excitement turn into frustration. I too had a very similar experience last year.
I'm a sole IT guy at an org of about 50 people and walked into the place with some old early 90s PBX connected to some ancient PC. My boss (the COO basically) worked with our local telco, and they pushed a UC560 along with their private IP over T1 service. I was looking into a number of hosted PBX solutions, but this is what he went with. The vendor promised us a simple install and their experts would handle everything.
So when the time came it turned out the install and support was sub-contracted to a firm out of NYC. The equipment was shipped to them, they then did config and shipped to us and came down to rack it all.
Of course I wanted to learn all I could about it, having never had any Cisco experience, I was respectful of not doing something to trip them up, but it came quickly clear they had no idea what they were doing. Each problem resulted in them calling Cisco and working through it.
The box ended up so horribly broken (most features didn't work) a Cisco tech said it should be wiped and reinstalled and this time don't touch the CLI. I ended up insisting they do that and find out that since the major phone company didn't have a template for their SIP service, it had to be tweaked in the CLI anyway.
We again suffered problems. Some of the rookie mistakes they made were:
* Couldn't get the SIP service to register. They changed the default route to the private T1 and it worked but then our remote phones couldn't connect. Changed the default route back to public internet and SIP wouldn't register. I kept saying "just put in a routing rule for the registrar IP in" but their tech couldn't grok that, so I finally just did it myself.
* One way audio. After them working for days trying to figure it out I just did trial and error and found out that the QOS settings they used weren't supported by the SIP provider.
* They set my WAN IP to my local LAN IP, which I still need to fix.
In short, in a period of a few weeks I ended up knowing more than the techs assigned to our account. I'd know the answer to a problem and then just sit and wait and see how long it would take for them to figure it out.
It's been running for over a year now OK but has some issues. I can't get a backup from it. I've tried via CLI, CCA, and the web interface. It fails when backing up voice mail data. Something I'll need to call Cisco for when I get a chance.
Honestly, these "experts" just called Cisco support for just about everything. It was clear the company only had one person who knew what he was doing but he was stretched thin and our tech had issues getting any time with him.
Basically I have *no* idea how one of these systems is put into a small business that doesn't have a competent person on staff to manage it. Just something simple like letting the receptionist toggle a night message on and off as needed instead of being on a schedule required me to do a lot of research to end up with some hybrid between night service and scheduled business hours.
